12. Let X be a positive random variable whose expectation equals to 5. Consider the probabilitiesthat: P(X ＜10) and P(X ≥ 8). Which of the following statement is the most correct one?
(A)P(X ≥ 8)＞0.7；
(B)P(X＜10)＞0.5
(C)P(X＜10)＜0.3；
(D) P(X＜10) ＜ 0.4；
(E) P(X＜8)＜0.2.