In the Text the Authors Distinguish Between Effectiveness Studies (Which

Multiple Choice

In the text the authors distinguish between effectiveness studies (which are designed to find out whether a therapy works in the real, day-to-day clinical practice) and efficacy studies. How are effectiveness studies different from efficacy studies?

A) Effectiveness studies involve unhappy couples.
B) Efficacy studies are usually experiments with some kind of control group.
C) Effectiveness studies tell us whether a therapy works in a controlled laboratory setting.
D) Effectiveness studies and efficacy studies do not differ in any important way.