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