FIGURE 29-8 -A Metallic Frame Moving Along the Positive Direction Enters a Direction

FIGURE 29-8
-A metallic frame moving along the positive direction enters a region of space with a uniform magnetic field pointing in the positive z direction as shown in Fig. 29-8. In what direction should a force be applied to the frame to keep it moving at a constant speed while it is entering the field?

A) negative x
B) positive x
C) positive y
D) negative y
E) positive z