The passage gives a brief overview of the history of mad cow disease. It details when and how it started, the spread of the disease, and the efforts taken to eradicate it.
Out of the following fragments, the one with the prepositional phrase is "during the darkest night." The correct answer is C.
There would be no powerful will bending hers in that blind persistence with which men and women believe they have a right to impose a private will upon a fellow creature. It says that as a result of her husband's death there would be no powerful will bending hers, So she is free from her husband's "control".
