(A) due to minority carrier electrons in the transition region which are accelerated by the electric field to energies sufficient to free electron-hole pairs via collisions with bound electrons.
<\p> (B) in a reverse biased p-n diode in which the electric field enables tunneling of protons from the valence to the conduction band of a semiconductor,
(C) in a reverse biased p-n diode in which the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor
(D) due to a decrease in depletion layer
