An experiment investigated the effect of length and repetition of tv ads on students choosing to eat at del taco. all 60 students watched a 40-minute television program that included ads for del taco. some students saw a 30-second commerical; others a 90-second commerical. the same commerical was shown either 1, 3, or 5 times during the program. after the viewing, each student was asked to rate their craving for del taco on a scale of 0 to 10. what is the response variable? a. 1, 3, or 5 commercials during the 40-minute television program b. 40-minute television program c. 60 students d. 30-second and 90-second commericials e. craving for del taco on a scale of 0 to 10