单选题 The central limit theorem concerns the sampling distribution of the:

A. population mean.
B. sample mean.
C. population standard deviation.

【正确答案】 C

【答案解析】The central limit theorem tells us that for a population with a mean m and a finite variance σ², the sampling distribution of the sample means of all possible samples of size n will approach a normal distribution with a mean equal to m and a variance equal to [*] as n gets larger.