Hi Ishika

The correct option is 1) 'Na+ reabsorption requires energy'.

Explanation

The nephron is  composed of Bowman's capsule, proximal convoluted tubule, Loop of Henle and distal convoluted tubule . In distal convolutes tubule reabsorption of Na+ and water takes place which is active process i.e requires energy.

Thus, the correct answer is 'Na+ reabsorption requires energy'.

Thankyou