What Is a Serious Drawback to Using Analogue Studies

What is a serious drawback to using analogue studies?

A) They require larger samples than do other types of experimental studies.
B) Although the research offers high levels of control, the findings may not apply to anyone outside the sample studied.
C) Although the external validity of such research is strong, internal validity is usually weak.
D) It is difficult to gain the statistical significance needed for such studies to provide meaningful results.