Answer:
Option B, Dolphin
Step-by-step explanation:
Nekton are animal species that live in water (ocean or sea). They mostly reside in the photic or aphotic zone of ocean. They are able to locomote with in the water by swimming on their own (irrespective of direction of ocean currents). The mostly feed on phytoplankton, zoo plankton or smaller nekton. Some common example of nekton are – fish, shrimp, dolphin, turtles etc.
Hence, option B is the correct answer