What, If Anything, Is Wrong with Over-Generalizing the Findings of a Study

Multiple Choice

What, if anything, is wrong with over-generalizing the findings of a study that has a very small sample size?

A) Nothing is wrong because sample size is irrelevant.
B) Random assignment is typically not used in studies with small samples.
C) The subjects may share a characteristic that does not occur across the chosen population.
D) Studies with small sample sizes do not have control groups.