An Electron and a Positron Annihilate Each Other, Emitting Two

Multiple Choice

An electron and a positron annihilate each other, emitting two identical photons in the process. What is the wavelength of these photons? The mass of an electron or positron is 9.11 × 10^-31 kg and h = 6.63 × 10^-34 Js.

A) 1.21 × 10^-12 m
B) 1.73 × 10^-12 m
C) 2.43 × 10^-12 m
D) 3.07 × 10^-12 m
E) 3.46 × 10^-12 m