Problem 15. (2.5 %) Suppose X is uniformly distributed over [0,4] and Y is uniformly distributed over [0,1]. Assume X and Y are independent. Let Z = X+Y. Then (A) fz(4.5) = 0(B) fz(4.5)=1/8 (C)fz(4.5)= 1/4(D) fz(4.5)=1/2