Question

The direction of the magnetic field is determined by which of the following?
A. energy of the current
B. magnetic domain
C. magnetic force
D. direction of the current

Answer 1

D.
Energy of current doesn't alter the direction, but the magnitude of magnetic field.
If I recall, the magnetic field determines the magnetic domain.
Magnetic force is the result of a moving charged particle moving across a magnetic field.
A magnetic field can be generated by passing a current through a conductor, and if we reverse the direction of the current, we reverse the direction of the field, hence D.

Answer 2

Answer is D
And You can check it by using Right Hand Thumb Rule