What is a mercenary?

a.
a person hired to obtain supplies for an army

b.
a soldier hired to fight for another country

c.
a general hired to train foreign troops

d.
a commander in charge of an entire force

Conflict often developed between and the pope over how much influence the pope had over choosing local church officials. fill in the answer! like i mean tell me the answer! i am desperate! its the last question of the test so ! asap