3. Let X be an exponential random variable. Without any computations, tell which one of the following is correct. Explain your answer.

(a) E[X2|X > 1] = E[(X + 1)2];

(b) E[X2|X > 1] = E[X2] + 1;

(c) E[X2|X > 1] = (1 + E[X])2.