Answer:
A. The sample has more than 30 grade-point averages.
B. If the population of grade-point averages has a normal distribution
Step-by-step explanation:
According to the Central Limit Theorem, if the sample size is big enough(>30) and the population distribution is normal (population of grade point averages) then that sample mean be treated as a value from a population.
Population of statistics students is out of concern in this context since grade-point averages are sampled.