Question: Design a one-way experiment to test each of the following research hypotheses:
a. The more a person tries not to think of something, the more he or she will actually end up thinking about it.
b. People are more helpful when they are in a good mood than when they are in a bad mood.
c. Consumption of caffeine makes people better at solving mathematics problems.
d. People learn faster before they eat a big meal than after they eat a big meal.