A simple random sample of 100 people is selected from a population which has a true standard deviation of 2 years. Thus, the standard error of the sample mean is . 2, when n = 100. If the sample size of n = 400 had been used instead, the standard error of the sample mean would be: a) Twice as large as when n = 100 b) Four times as large as when n = 100 c) One-half as large as when n = 100 d) One-fourth as large as when n = 100 e) None of the above