不太理解 A 为什么不对

问题如下：

Question The sampling error is best described as the:

选项：

A.sample standard deviation divided by the square root of the sample size.

B.difference between the observed value of a statistic and the quantity it is intended to estimate.

C.sum of squared deviations from the mean divided by the sample size minus one.

解释：

B is correct. The sampling error is the difference between the observed value of a statistic and the quantity it is intended to estimate.

A is incorrect. The sample standard deviation divided by the square root of the sample size is the standard error of the sample mean.

C is incorrect. The sum of squared deviations from the mean divided by the sample size minus one is the sample variance.