How can a compass be used to determine if an electromagnet is working?

Question

anonymous · Answer

A.
Move the compass near the electromagnet. If the compass needle points toward the electromagnet, then the electromagnet is working.
 
 B.
If the compass and the electromagnet are put side-by-side, and the compass attracts the electromagnet, then the electromagnet is working.
 
 C.
Move the compass near the electromagnet. If the compass needle points away from the electromagnet, then the electromagnet is working.
 
 D.
If the compass and the electromagnet are put end-to-end, and the compass repels the electromagnet, then the electromagnet is working.

anonymous · Answer

A.