Under Which of the Following Circumstances Is It Impossible to Construct

Multiple Choice

Under which of the following circumstances is it impossible to construct a confidence interval for the population mean?

A) A non-normal population with a large sample and an unknown population variance.
B) A normal population with a large sample and a known population variance.
C) A non-normal population with a small sample and an unknown population variance.
D) A normal population with a small sample and an unknown population variance.