You design an experiment to test the hypothesis that consuming caffeine increases a person's chances of developing a headache. Participants in the experimental group will be told to drink 8 ounces of caffeinated soda in the morning once a day for 10 days, and to abstain from drinking any other caffeinated beverages or soda. Which of the following is an appropriate control group for your experiment? a) A group that drinks 8 ounces of decaffeinated hot coffee (no caffeine) in the morning once a day for 10 days and abstains from drinking any other caffeinated beverages or soda
b) A group that drinks 8 ounces of caffeinated soda once a day for 10 days in addition to their normal beverage habits
c) A group that drinks 8 ounces of decaffeinated soda (no caffeine) in the morning once a day for 10 days and abstains from drinking any other O caffeinated beverages or soda.
d) A group that does not drink soda (caffeinated or decaffeinated) or other caffeinated beverages for 10 days