Aziprol and berpinol are two new drugs that have been developed in the cold and flu market. both drugs have passed tests for their safety and they have been approved for sale. however, a medical research team is studying the effect of these drugs on drowsiness. if either drug has an impact on drowsiness, labels must be placed on the packaging of the drugs. the team runs an experiment. the team believes that gender may have an impact on the results of the experiment, so 200 volunteers are gathered: 100 men and 100 women. each gender group is divided up into four groups of 25 people each. people are assigned to these groups on a completely random basis. for each gender, the four groups are assigned the following treatments: one group receives a placebo of both drugsone group receives a dose of aziprol and a placebo for berpinolone group receives a placebo for aziprol and a dose of berpinolone group receives a dose of both drugsthe subjects are unaware of which treatment they are receiving. it is found that aziprol does not have any significant effect on drowsiness, but berpinol does. complete the following statements.
a)in this experiment an example of a control group is .
b)this experiment is blinded because