The electron will be accelerated much faster than the proton.
Work Step by Step
Consider Newton's second law, F = ma, to analyze the magnitudes of the accelerations. The proton is about the electron, and be in the direction of the electric field. How much less? Since the mass of the proton is about 1800 times greater than the mass of the electron, its acceleration will be about 1/1800 that of the electron.