Correct Answer: D is the daughter-in-law of T

Solution : Given:
A # B ⇒ A is the husband of B,
A @ B ⇒ A is the daughter of B,
A & B ⇒ A is the sister of B.

As per the given information, the family tree will be as follows –

Here, the quadrilateral represents the male and the circular figure represents the female in the figure.
Now, let's check the options –
First option: S is the maternal grandfather of Q – From the above family tree, it is evident that S is the maternal grandfather of Q. So, this option is correct.
Second option: P is the daughter of K – From the above family tree, it is evident that P is the daughter of K. So, this option is correct.
Third option: T is the mother of K – From the above family tree, it is evident that T is the mother of K. So, this option is correct.
Fourth option: D is the daughter-in-law of T – From the above family tree, it is evident that D is the son-in-law of T. So, this option is incorrect.

Hence, the fourth option is correct.