A large pharmaceutical company is trying to determine whether a drug aptly named Recall-Pro can increase your short-term memory capacity. The company prepares a double-blind study as follows:


Step 1: A randomly selected pool of individuals is brought to a clinic and is evaluated for any existing health conditions that may impair the results of this experiment.


Step 2: The remaining individuals are split into two groups: a treatment group and a control group.


Step 3: The control group receives a placebo, but neither the researcher nor the individuals know this.


Step 4: The treatment group receives Recall-Pro, but neither the researcher nor the individuals know this.


Which step is flawed in the double-blind study? Why?

A.Step 1; health screening should not eliminate participants from the study

B.Step 2; it does not specify whether the two groups are chosen randomly

C.Step 3; the control group does not receive the placebo

D.Step 4; members of the treatment group should know that they have received the medication