The first response is the only claim that makes sense. To check, let's use the process of elimination.
Second: Calling the scientists' surveys unsophisticated is irrelevant and does not prove that the original claim is correct.
Third: This option does not address the points made by the counterclaim and instead pushes the original idea. It is important to remember that it is supposed to be a response, not a new statement.
Fourth: This response gives up on the original idea and ends the debate, with the counterclaim winning.
