In One Study Described in the Textbook (Geier Et Al

In one study described in the textbook (Geier et al., 2012) , college students were given tubes of potato chips to eat while watching a movie. In some tubes, every 7th chip was died red. What was the independent variable in this study, and what did the researchers find?

A) Whether the tubes contained red chips was the independent variable. Participants given tubes with red chips ate 10% less than did the other participants.
B) Whether the tubes contained red chips was the independent variable. Participants given tubes with red chips ate 50% less than did the other participants.
C) How many chips participants ate was the independent variable. Participants given tubes with red chips ate 10% less than did the other participants.
D) How many chips participants ate was the independent variable. Participants given tubes with red chips ate 50% less than did the other participants.