There Are Several Steps an Investigator Must Take in Carrying

There are several steps an investigator must take in carrying out the general procedure for drawing causal inferences based on the natural groups design.Which of the following is not one of the steps an investigator must take?

A) Select a second individual differences variable that would be expected to interact with the primary individual differences variable.
B) Develop a theory explaining why a difference should occur between groups differentiated on the basis of an individual differences variable.
C) Select an independent variable that can be manipulated and that should influence the likelihood that the theoretical process will occur.
D) Strive to produce an interaction effect between a manipulated independent variable and the primary individual differences variable.