An Paired-Samples T-Test Is Used to Test For

An paired-samples t-test is used to test for:

A) Differences between means of groups containing different entities when the sampling distribution is normally distributed, and the data have equal variances and are at least interval.
B) Differences between means of groups containing the same entities when the sampling distribution is normally distributed, and the data have equal variances and are at least interval.
C) Differences between means of groups containing different entities when the sampling distribution is not normally distributed.
D) Differences between means of groups containing the same entities when the sampling distribution is not normally distributed and the data do not have unequal variances.