If the Parameter of an Exponential Distribution Is 1, Then $\ge$

Multiple Choice

If the parameter of an exponential distribution is 1, then which of the following is not true?

A) The density function is e^-x for x $\ge$ 0.
B) The mean is equal to 1.
C) The standard deviation and variance are both equal to 1.
D) All of these choices are true.