What does a high standard error indicate regarding the sample mean?

A high standard error indicates that the sample mean is expected to vary significantly from the population mean. The standard error is a measure of how much the sample mean is expected to fluctuate from sample to sample due to random sampling variability. When the standard error is high, it suggests that there is considerable uncertainty around the estimate of the population mean based on the sample data. This can occur when the sample size is small or when there is a high level of variability in the data.

In contrast, a low standard error would suggest that the sample mean is a more reliable estimate of the population mean, as it indicates less variability between different sample means. Thus, recognizing a high standard error serves as a warning that the sample mean may not accurately reflect the population mean, making option B the correct assessment.