A circular loop of wire carries a constant current. If the loop is placed in a region of uniform magnetic field, the net magnetic force on the loop is

A、 perpendicular to the plane of the loop, in a direction given by a right-hand rule.;

B、perpendicular to the plane of the loop, in a direction given by a left-hand rule.;

C、 in the same plane as the loop.;

D、zero.;

E、The answer depends on the magnitude and direction of the current and on the magnitude and direction of the magnetic field.