## Questions 22-23
An electron and a positron, each of mass 9.1×10−31 kilogram, are in the same general vicinity and have very small initial speeds. They then annihilate each other, producing two photons.
23. What is the angle between the paths of the emerging photons?
(A) 0∘
B) 45∘
C) 90∘
D) 180∘
(A) 0∘