In the tempest, why does ariel do as prospero orders him?

a.
ariel knows that prospero intends to get revenge on those who have wronged both of them, so he is eager to .

b.
ariel wishes to marry miranda, so he will do whatever it takes to impress and her father, prospero.

c.
prospero freed ariel from the evil witch sycorax, who had imprisoned ariel in a pine tree for 12 years.

d.
prospero is ariel's father, and ariel's misdeeds are the reason that the family was exiled to the island.