Electrons Traveling at a Speed of V₀ = 3 ×

Electrons traveling at a speed of v₀ = 3 × 10⁷ m/s pass through the deflection plates. The electric field between the plates is E = 5000 V/m and spans a distance of x₁ = 5 cm. The electrons then travel a further distance of x₂ = 40 cm along the x-axis. In which direction should the magnetic field be applied so that the electron lands undeflected at a?

A) 1
B) 2
C) 3
D) 4
E) 5