Suppose a Is Religiosity and B Is Happiness

Multiple Choice

Suppose A is religiosity and B is happiness. Can one conduct a randomized experiment to find out whether A affects B?

A) Yes, assign individuals to one of the major religions and later ask how happy they are.
B) Yes, assign individuals to a level of happiness and later ask them what their religious preference is.
C) No random assignment can be made.
D) none of these (a, b, c)