Consider the following population probabilities x -4-3-2-101234 pix) .02 .07 .10 .15 .30 .18.10 .06 .02 Let x1,..., xn be a random sample from this population. If n=20, then the sample mean has mean and standard error of the mean of: O a) 0.01 and 0.2711, respectively. 0 b) 0 and 0.3131, respectively. 0 c) 0.01 and 0.2425, respectively. 0 d) -0.01 and 0.2214, respectively. 0 e) 0 and 0.3834, respectively