In a Graph of the Results from an ABAB Reversal

Multiple Choice

In a graph of the results from an ABAB reversal design,which of the following features justifies a conclusion that the treatment causes changes in behavior?

A) the size of the change in behavior when the treatment is first introduced
B) the time delay between the introduction of the treatment and the first change in behavior
C) a permanent change in behavior that continues even after the treatment is withdrawn
D) repeatedly demonstrating that behavior changes consistently when the treatment is introduced,withdrawn,and introduced again