Define exploit to treat unfairly by using someone's work or ideas and giving them very little in return

a secret agreement or cooperation especially for an illegal or deceitful purpose

to give someone their fair share of credit or pay​

to treat unfairly by using someone's work or ideas and giving them very little in return

Explanation:

B) is the definition of the word collusion, and C) is the opposite of the word exploit.

i think the answer is a and i hope this ; ))

b. florence

d. milan