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, 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 on a scale of 0 to 10.

(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 observational study because the study investigator observed the students’ ratings on their craving for the Sub-U-Like sandwich.
D. An experiment because the study investigator controlled the amount of exposure to advertisements the participating students received.


(b) What are the subjects in the "Sub-U-Like" study?
A. The 50-minute television program
B. The craving for a Sub-U-Like sandwich on a scale of 0 to 10
C. The 60 students
D. The effect of the length and repetition of the TV commercials
E. One, three, or five commercials during the 50-minute television program


(c) What is/are the response variables in the "Sub-U-Like" study?
A. The length and repetition of the TV advertisements
B. The 60 students
C. The 50-minute television program
D. Craving for Sub-U-Like on a scale of 0 to 10
E. One, three, or five commercials during the 50-minute television program


(d) How many treatments are there in the "Sub-U-Like" study?
Enter your answer as a number (e.g. 1), not as text.
Answer: