Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical value to /2, (b) find the critical value Za /2, or (C) state that neither the normal distribution nor the t distribution applies. Here are summary statistics for randomly selected weights of newborn girls: n = 199, x = 28.8 hg, s =6.5 hg. The confidence level is 90% . . . . . Select the correct choice below and, if necessary, fill in the answer box to complete your choice. OA. ta/2= (Round to two decimal places as needed.) OB. Za/2= (Round to two decimal places as needed.) O C. Neither the normal distribution nor the t distribution applies