What question is Maya most likely trying to answer?

A. How does the type of material used in the core affect
the strength of an electromagnet?

B. How does the number of loops of wire affect the
strength of an electromagnet?

C. How does the speed at which an iron bar is removed
from wire loops affect the strength of an
electromagnet?

D. How does the thickness of the wire affect the strength
of an electromagnet?

Thank u :)