Most of what we need to answer this question is located in paragraph four, which I will try to summarize.
Political theorists criticize the application of classical theory to the civil rights movement for the following reasons:
1. Classical theory minimizes political factors and focuses on psychological dysfunction. 2. Classical theory reduces complex social structures to simple paradigms. 3. The concept of "strain" is not unique or predictive
The question is basically asking us, what do the political theorists think of the social psychologists who use classical theory?
E gives us the right answer, as seen in argument 1 listed above.
You asked why D is incorrect. This is a tough one, because it does sound a lot like E. However, they are not saying the same thing. I will refer you to line 41: "the classical theory trivializes the political ends of movement participants." The social psychologists who employ classical theory are not trying to explain the political ends through psychology. Rather, they are disregarding the political aspect altogether.
