Once a writer identifies counter-arguments opponents might make, it would be silly to announce those counter-arguments and not argue against them. So after stating the objections of opponents, most writers will refute or rebut the objections. It's possible to construct an entire argument out of objections and rebuttal. Good rebuttal usually requires evidence, so don't forget to look for support for the rebuttal position in that part of an argument. Like all evidence, rebuttal evidence should be sufficient, accurate, and credible.