An Electron Travels in the +X Direction with a Velocity

Multiple Choice

An electron travels in the +x direction with a velocity of 1.5 *10⁶ m/s. It enters an E * B velocity selector that utilizes a cross electric and magnetic field to produce a zero net force on the particle. The magnitude of the magnetic field is 0.10 T in the +y direction. The magnitude of the electric field required to produce a straight-line trajectory is

A) 1.5 * 10⁵ V/m in the +z direction.
B) 1.5 *0⁵ V/m in the -z direction.
C) 1.5 * 10⁵ V/m in the +y direction.
D) 1.5 * 10⁵ V/m in the -y direction.