The information regarding a proton moving north was necessary to fix the direction of the magnetic field. Otherwise, an upward magnetic force on an eastward-moving proton could be caused by a magnetic field pointing anywhere northeast or northwest. The relative strengths of the forces, with the electric force larger than the magnetic force and both much larger than the gravitational force, all for typical field values found in nature. An electron and proton moving with the same velocity enter a uniform magnetic field. In what two ways does the magnetic field affect the electron differently from the proton?

a. The magnetic field produces a larger acceleration of the electron.
b. The proton moves in a straight line while the electron is pushed to one side of its path.
c. If the proton is pushed to the right, the electron is pushed to the left.
d. The magnetic field produces a larger acceleration of the proton.