The Direction of the Magnetic Field in a Certain Region

Multiple Choice

The direction of the magnetic field in a certain region of space is determined by firing a test charge into the region with its velocity in various directions in different trials.The field direction is:

A) one of the directions of the velocity when the magnetic force is zero
B) the direction of the velocity when the magnetic force is a maximum
C) the direction of the magnetic force
D) perpendicular to the velocity when the magnetic force is zero
E) none of the above