What Is the Factor That Makes the Between-Participants Posttest-Only Design

Multiple Choice

What is the factor that makes the between-participants posttest-only design a "strong" experimental design and the nonequivalent posttest-only design a weak design?

A) the between-participants posttest-only design involves manipulating variables and the nonequivalent posttest-only design does not
B) testing participants twice changes their performance in the nonequivalent posttest- only design
C) the between participants posttest-only design uses two groups of different participants and the nonequivalent posttest-only design used the same participants
D) random assignment helps insure that the two experimental groups are essentially Equivalent at the outset