Suppose that $X$ is a real valued random variable and $E[\exp X]=2$. Then, which of the following must be $\text{TRUE? Hint:}$ $(\exp (x)+\exp (y)) / 2 \geq \exp ((x+y) / 2)$.
- $E[X]<\ln 2$
- $E[X]>\ln 2$
- $E[X] \geq \ln 2$
- $E[X] \leq \ln 2$
- None of the above