An electron moving in the positive y direction, at right angles to a magnetic field, experiences a magnetic force in the negative x direction. What is the direction of the magnetic field?
a) It is in the negative z direction.
b) It is in the negative x direction.
c) It is in the positive y direction.
d) It is in the positive z direction.
e) It is in the positive x direction.
I was pretty sure the answer was in the negative x direction but I only have one more try and that isn't the answer. Any help would be appreciated!