This is due today a study involving middle-aged adults was designed to determine the relationship between the amount of caffeine consumed during the day and the time required to fall asleep at night. what are the independent and dependent variables for this study? a. the independent variable is the amount of caffeine consumed, and the dependent variable is the time required to fall asleep. b. the independent variable is the amount of caffeine consumed, and the dependent variable is the age of the people. c. the independent variable is the time required to fall asleep, and the dependent variable is the amount of caffeine consumed.. d. the independent variable is the age of the people, and the dependent variable is the time required to fall asleep.