________ explains human personality in terms of future goals

Dr. Halk is studying the influence of getting older on intelligence. He tests a group of first graders, a group of third graders, and a group of sixth graders. They are all tested in one day. This is an example of _______ research

a. cross-sectional b. longitudinal c. mixed design d. fixed effects

Caffeine acts by blocking adenosine receptors

Indicate whether the statement is true or false.