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、perpendiculartotheplaneoftheloop,inadirectiongivenbyaright-handrule.;
B、perpendiculartotheplaneoftheloop,inadirectiongivenbyaleft-handrule.;
C、inthesameplaneastheloop.;
D、zero.;
E、Theanswerdependsonthemagnitudeanddirectionofthecurrentandonthemagnitudeanddirectionofthemagneticfield.