Organism that swim freely in the water and possess locomotion enabling them to have independent drifting movement:

Correct option is C

Correct Answer: (c) Nekton
Explanation:
→ Nekton are organisms capable of active swimming (fish, squid) and can move independently of water currents — unlike planktonic drifters.
→ They control their position and migration in the water column.
Information Booster:
→ Neuston/pleuston live at the air–sea interface; ooze refers to deep-sea sediment.
Additional Information (Other Options):
(a),(b),(d): not free-swimming nektonic organisms.