Hector spent the last three months on a winter fishing boat in alaska. he was doing research on population levels of fish for conservation efforts. hector most likely works in what?

Hector works in marine biology field. He was studying the fish population levels at Alaska. That's what a marine biologist can do. Marine Biology takes care of studying the marine life and organism in the sea.

the answer is   c the cold war

what is margin again? i’m confusion