Hosea Is Studying the Relationship Between Caffeine Consumption and Problem-Solving

Multiple Choice

Hosea is studying the relationship between caffeine consumption and problem-solving ability.Which of the following is a categorical way to operationalize caffeine consumption?

A) The number of glasses of soda consumed in a day
B) The number of milligrams of caffeine consumed during the study
C) The frequency of buying coffee drinks
D) Whether the participant drank a soda in the 24 hours prior to the study
E) All of the above are categorical ways of operationalizing caffeine consumption