The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.

A. A decrease in the concentration of NaCl and glucose and an increase in the water level.

B. A decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose.

C. No net change in the system.

D. A decrease in the concentration of NaCl and a decrease in the water level.

E. No change in the concentration of NaCl and glucose and an increase in the water level.

Thus, sodium chloride from the arm of tube with high NaCl concentration will start moving towards the arm with low NaCl concentration and hence, the salt concentration will reduce on side A.

The volume will not remain constant as the concentration of NaCl on side A will reduce thereby decreasing the water level from its initial mark

Hence, option D is correct