Explanation
Correct answer: A.
Choice A is the best answer. It best describes the main idea of the text. The text starts by saying that historians of the Black Power movement are too reliant on openly ideological works, which were written mostly by men, as sources. The text then describes Farmer’s research: she has shown that including other kinds of sources leads to a better understanding of the Black Power movement and the role Black women played in it.
Why the other choices are wrong
Choice B
Choice B is incorrect. This doesn’t describe the main idea of the text. In fact, it conflicts with the text. The text says that historians have relied on "essays and other explicitly ideological works," which suggests that they have studied at least some of the intellectual dimensions of the Black Power movement.
Choice C
Choice C is incorrect. This doesn’t describe the main idea of the text. The text never mentions how other historians of the Black Power movement view Farmer’s use of unconventional sources. In fact, the text itself argues in favor of Farmer’s research, claiming that it has led to a "much better understanding of the movement."
Choice D
Choice D is incorrect. This doesn’t describe the main idea of the text. The text never mentions what any figures in the Black Power movement thought about women’s roles in the movement.