Why is it necessary to have interneurons?

A To send messages to the body.
B To assist afferent and efferent neurons in their jobs to send messages.
C To associate sensory signals with objects.
D To send messages to the central nervous system.
E To move our muscles.

Capelin are fish found in the atlantic and the arctic oceans. in spring and summer, capelin are usually seen in the region between iceland and greenland. what is the most likely reason for the presence of capelin in these regions? a) these regions are rich in plankton during summer. b) capelin need to migrate from deep to shallow water. c) fishing boats do not visit these regions in the summer. d) capelin need to move into fresh water during this period.