Dr Fletcher Is Interested in Whether Joining a Fraternity/sorority Causes

Multiple Choice

Dr. Fletcher is interested in whether joining a fraternity/sorority causes people to become more concerned about their attractiveness and appearance. He recruits a group of 55 freshmen (25 males, 30 females) who are planning to go through fraternity/sorority recruitment on his campus. After they join, he gives them a measure of attractiveness concern/appearance concern (the Body Concern Scale) .
Which of the following would Dr. Fletcher need to do to his current study design to make it an interrupted time-series design?

A) Recruit a group of participants who joined a fraternity/sorority at a different school
B) Take measurements of body concern before and after joining a fraternity/sorority
C) Measure body concern using a different measure than the Body Concern Scale
D) Add an additional variable, such as self-esteem