Which type of research study is set up so that neither subjects nor investigators know which is the active group and which is receiving a placebo?
a. Double blind
b. Clinical trial
c. Case control
d. Epidemiological

Respuesta :

A) Double blind is the research study set up so that neither subjects nor investigators know which is the active group and which is receiving a placebo. 
The best answer to the question above would be letter a. A type of research study set up so that neither subjects nor investigators know which is the active group and which is receiving a placebo is a double blind type of research method.