What is the Columbian exchange

so the story tells of someone named kaushik choudhuri, but he does not narrate the story, a girl named hema does. hema tells the story in a second person point of view because you (the reader) are supposed to be the boy named kaushik.

here's an excerpt i found: "i was ushered into the fitting room, your mother watching approvingly as i took off my coat and sweater and tried on the bra."

source:

the answer is c, all the other options are things they are known for.

hope this ☺️