The correct answer is B: by responding to counterclaims in a respectful way.
A major part of your argument lies in the way that you respond to counterclaims. Your readers will respect your opinion if you respect others'. However, this does not mean that you need to agree with counterclaims. If you dismiss counterclaims as unreasonable, you also have less to work off of in your essay. You need a counter argument to be able to express your viewpoint more clearly. Criticizing any counterclaim sources can be considered unreasonable on your side, and it does not prove your point any further.