5. A parallel plate capacitor, with air dielectric, is charged by a battery after which the battery is disconnected. A slab of glass dielectric is then slowly inserted between the plates. As it is being inserted,
(A) a force repels the glass out of the capacitor.
(B) the glass makes the plates repel each other.
(C) no force acts on the glass.
(D) a net charge appears on the glass.

(E) a force attracts the glass into the capacitor.