Pair Production Can Occur If

Multiple Choice

Pair production can occur if:

A) the energy of two photons is greater than the combined mass-energy of a particle-antiparticlepair.
B) only virtual particles are produced.
C) photons are at the event horizon of a black hole.
D) one particle is struck by a sufficiently high energy photon that a pair of electrons is formed.
E) the particle and antiparticle have opposite spins.