A study investigated the effect of the length and the repeti

A study investigated the effect of the length and the repetition of TV advertisements on students\' desire to eat at a Sub-U-Like sandwich franchise. Sixty students watched a 50-minute television program that showed at least one commercial for Sub-U-Like during advertisement breaks. Some students saw a 30-second commerical, some saw a 60-second commercial, others a 90-second commerical. The same commerical was shown one, three, or five times during the program. After the viewing, each student was asked to rate their craving for a Sub-U-Like sandwich from the set {\"Don\'t want to eat\", \"Neutral\", \"Want to eat\"}.

(a) What kind of study is this?
A. An experiment because the study investigator compared the degree of craving between different amounts of exposure to advertisements in the study.
B. An observational study because there was no control group.
C. An experiment because the study investigator controlled the amount of exposure to advertisements the participating students received.
D. An observational study because the study investigator observed the students

Solution

my answer is

a) C

b)A

c)D

d)A