A researcher collects a simple random sample of grade-point averages of statistics students, and she calculates the mean of this sample. Under what conditions can that sample mean be treated as a value from a population having a normal distribution? Select all that apply.

A. The sample has more than 30 grade-point averages.

B. If the population of grade-point averages has a normal distribution

C. The researcher collects more than 30 samples.

D. If the population of statistics students has a normal distribution.