We Are Interested in Testing a Null Hypothesis About a Population

Multiple Choice

We are interested in testing a null hypothesis about a population mean  being equal to a specified value using a simple random sample of size 25.In the past the population variable has shown a slight tendency to non-Normality (slight skewness but no strong outliers) .Why can we safely use a t procedure in this testing situation?

A) The sample standard deviation is robust against such things as outliers.
B) The one-sample t procedure requires that the sample be selected using an SRS design,which is what was done in this case.
C) The t procedures are quite robust against non-Normality,unless there are strong outliers.
D) All of the above are reasons.
E) Only B and C are justifications for using the t procedure here.