Correct Answer: Spleen

Solution : The correct answer is Spleen.

The spleen is known as the graveyard of RBCs. They have a life span of 120 days and after they die, they are ingested by free macrophages in the spleen. It helps in purifying blood, removes old and damaged cells and controls their levels. It also contains White Blood Corpuscles (WBC) and fights antigens that enter the bloodstream. It is one of the largest lymphatic organs in the human body.

Correct Answer: show him the place where she and her husband spent their evenings

Solution : The fourth option is the correct answer.

Explanation:
The narrator's cousin's wife took him to a lake to show him the place where she and her husband spent their evenings. The passage mentions,( My cousin's wife said, 'Let me show you where we spend some of our evenings'). This clearly indicates that the purpose of visiting the lake was to share with the narrator the location where she and her husband often spent their leisure time.

Correct answer: Show him the place where she and her husband spent their evenings.

Correct Answer: enhance

Solution : The correct choice is the third option.

Enhance means to increase, and it helps convey that the resources will help increase the knowledge.

Correct Answer: compassionate

Solution : The correct choice is the third option.

Explanation:
The antonym for ruthless is compassionate. 
Ruthlessness refers to a lack of empathy or mercy, while compassion involves showing kindness and concern for others.

The meanings of the other options are as follows:

• Inhuman: lacking human qualities, often associated with cruelty.
• Savage: Extremely cruel, violent, or uncivilised.
• Mean: unkind or cruel in nature.

Therefore, the correct answer is compassionate.

Correct Answer: Maharashtra

Solution : The correct option is Maharashtra.

According to the 2011 Census, Maharashtra is the second-most populous state in India. Maharashtra's population constitutes 9.28% of India's overall population. Approximately 54.78% of Maharashtra's total population lives in rural areas.

Correct Answer:

Solution : According to the question figure –
1. In the given series, the horizontal lines are increasing and the vertical lines are decreasing successively.
2. The geometrical shape changes between triangle and square while moving along the corners in a clockwise direction.
So, following the above pattern, the required figure will be as follows –

Therefore, the complete figure is as follows – 

Therefore, the figure in the third option is the required figure. Hence, the third option is correct.

Correct Answer: The teacher said to the students, "Keep quiet."

Solution : The fourth option is the correct answer.

Steps of conversion:

The original reporting verb commanded is changed to said in the direct speech. 

The imperative command to keep quiet is rephrased as keep quiet. 

The reported speech is enclosed within quotation marks.

Therefore, the correct answer is: The teacher said to the students, "Keep quiet."

Correct Answer: Fathers, Uncles, Brothers

Solution : Let's check the options –
First option: Police Officers, Doctors, Nurses; These are the professions and do not have a common relation to them. Therefore, this is incorrect.
Second option: Artists, Fathers, Girls; some girls and fathers may be artists but there is no common region between fathers and girls. Therefore, this is not the correct relation.
Third option: Brothers, Males, Females; All brothers come under the category of males so, the circle of brothers completely lies under the circle of males but males and females do not have any common region. Therefore, this is incorrect.
Fourth option: Fathers, Uncles, Brothers; Some fathers may be uncles and brothers, and some uncles may be fathers and brothers. Similarly, some brothers are fathers and uncles. Therefore, all the terms have a common region between them.
The Venn diagram is as follows –

Hence, the fourth option is correct.

Correct Answer: 3

Solution : The error lies in the third part of the sentence.

There is an error in the subject-verb agreement in the sentence.

 The verb were should be replaced with was to convey the intended meaning that there was a decoration on the wall, which was a painting of a horse. The subject in the sentence The decoration is singular. Hence, the verb should also be singular. So, were should be replaced with was.

Therefore, the correct sentence should be: The decoration on the wall was a horse painting.

Correct Answer: The parcel had been delivered by the courier service.

Solution : The correct option is the third option.

Passive voice is the voice in which the object experiences an action rather than the person who performs the action. Hence, the object in the active sentence becomes the subject in the passive voice.

The structure of the past perfect sentence in the passive voice form is: "Singular object + had been + past participle form of the main verb + 'by' followed by the agent of the action."

Therefore, the passive sentence would be: "The parcel had been delivered by the courier service."