(C) The first is evidence that has been used to support a conclusion for which the argument provides further evidence; the second is the main conclusion of the argument. - Like option B, the role of BF1 is not correctly mentioned in this. Besides, BF2 is not the main conclusion of the argument. Second last statement (which is not bolded) is the main conclusion of the argument. Incorrect.
Can you clarify which portion of the paragraph is supposed to be the conclusion here? Is it "Nevertheless...cases are spurious"?
Heads down, stay focused, ignore the noise