Which electromagnet would have the most strength?

Responses
A An electromagnet with 5 coils.An electromagnet with 5 coils.
B An electromagnet with 10 coils.An electromagnet with 10 coils.
C An electromagnet with 15 coils.An electromagnet with 15 coils.
D An electromagnet with 20 coils.

D An electromagnet with 20 coils.