Researchers wish to determine if a new experimental medication will reduce the symptoms of allergy sufferers without the side-effect of drowsiness. To investigate this question, the researchers give the new medication to 50 adult volunteers who suffer from allergies. Forty-four of these volunteers report a significant reduction in their allergy symptoms without any drowsiness.
This is an example of
A. the establishing of a causal relationship.
B. a block design.
C. a randomized study.
D. a double blind experiment.
E. None of the above.
I think it's A, is it correct?