Johnson Is Hired by a Company to See If a New

Multiple Choice

Johnson is hired by a company to see if a new product,Topocal,will cause hair to grow on the heads of bald men.He recruits one thousand bald men,and randomly divides them into two groups:Five hundred (group A) rub Topocal on their scalps each day;the other five hundred (group B) rub a standard skin lotion on their scalps each day.After two months,Johnson checks to see what the results have been.He finds that there has been hair growth in 7 percent of group A and in 2 percent of group B.The category that best fits this study is

A) prospective observational study.
B) retrospective observational study.
C) randomized controlled experiment.