Alarge 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