Which of the following sources of radiation is manmade?

1. Atmospheric fallout from nuclear weapons testing
2. Cosmic radiation from the sun and beyond the solar system
3. Nuclear power plant accidents as a consequence of natural disasters

a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3

b. 1 and 3 only