Which of the Following Statements Is True

Multiple Choice

Which of the following statements is true?

A) The more variable the groups within a population are, the larger the sample needs to be to detect any real difference between the groups.
B) The more variable the groups within a population are, the smaller the sample needs to be to detect any real difference between the groups.
C) No matter how variable the groups within a population are, the size of the sample needed to detect a real difference between the groups is the same.
D) None of the above statements are true.