(Scenario III) the Researchers Who Conducted the Study Described in Scenario

Multiple Choice

(Scenario III) The researchers who conducted the study described in Scenario III were able to make a causal statement about the effect of caffeine on memory because:

A) they conducted their study in a laboratory setting.
B) they examined memory in only those who were unaccustomed to caffeine.
C) they randomly assigned participants to treatment conditions and controlled how much caffeine each condition received.
D) they performed an independent t-test.