Because they was a possibility that their family member would not return.
I think it’s A I’m not sure though if I’m wrong I’m sorry .
Answer:
Ariel as his name suggests is a spirit, ethereal, while Caliban is gross and bestial. Both are connected to the witch Sycorax who ruled the island before Prospero: Ariel was imprisoned by her, before being rescued by Prospero, while Caliban is her offspring. Both are servants of Prospero.
