Mega Corp hired permanent replacement workers when its union went out on strike seeking better ...

Mega Corp hired permanent replacement workers when its union went out on strike seeking better medical and retirement benefits. After the strike is over, Mega Corp
 A) must give the striking employees their jobs back since this was an economic strike.
 B) must give the striking employees their jobs back since this was an unfair labor practices strike.
 C) may hire additional workers without considering the striking employees who want their jobs back.
 D) does not have to give the striking employees their jobs back since this was an economic strike.