A region of space contains a uniform electric field produced by two large parallel metal plates. The potential of the top plate is +120V, and the potential of the bottom plate is +20V. Which statement best describes the direction of the electric field and the motion of a positive test charge released from rest between the plates?
a) The electric field points upward, and a positive test charge accelerates upward toward lower electric potential energy.
b) The electric field points upward, but a positive test charge accelerates downward because the electric force acts opposite to the field.
c) The electric field points downward, and a positive test charge accelerates downward toward lower electric potential energy.
d) The electric field points downward, but a positive test charge remains at rest because the potentials cancel out.