If an Observed Test Statistic Is Within the "Critical Region

If an observed test statistic is within the "critical region," what should we conclude?

A) The mean for a sample is different from the mean of the population.
B) It falls in an area of the sampling distribution that includes unlikely sample outcomes.
C) There is likely "no difference" or "no relationship" between the variables.
D) It falls near the centre of the sampling distribution.