Tough choice between A and C

@David the conclusion here is, "They are wrong, however." What are they wrong about? " . . . that no evidence exists to support the idea that the rate of extinction of animal species is now accelerating." This is exactly what (A) says, i.e. "There is evidence that the rate of extinction of animal species is accelerating." (C) does not pass the Must Be True prong of Main Point questions so it definitely cannot be the correct answer. Fish are used as an example to prove that there is evidence that the rate of extinction of animal species is accelerating. It is not used to show that the rate of extinction of North American fishes is parallel to the rate of extinction of all animal species taken together. Hope this helps! Please let me know if you have any other questions.

I think the author agrees that the rate can be determined in the future based on the current evidence, even If not in the exact number. If not, how can the author say "the is no evidence that the rate of extinction" is wrong? Am I correct if think this way?