Explanation
Correct answer: C.
Choice C is the best answer. Text 2 states that the researchers used cosmogenic nuclide dating to "avoid the potential for misdating" caused by the geology of Sterkfontein, which Text 1 describes as "challenging" and unreliable.
Why the other choices are wrong
Choice A
Choice A is incorrect. Neither text suggests that the A. africanus fossils have been "corrupted," but only that traditional dating methods are difficult in Sterkfontein because of floods and soil mixing where the fossils were found. Nothing is implied to have compromised the fossils themselves.
Choice B
Choice B is incorrect. This choice misreads Text 2. Text 2 agrees that stratigraphy and other methods are prone to error in the context of Sterkfontein: there's a "potential for misdating" when evaluating age based on soil layers and bones.
Choice D
Choice D is incorrect. Text 2 does not state that cosmogenic nuclide dating is applied to the fossils directly but rather to the breccia that surrounds them.