Answer :
The answer is A. to respectfully address any doubts or objections to the claim.
The counterargument is meant to look at points of the opposiing arguments, and then to address them in order to improve on your own argument. So, C and D are incorrect. You try to treat texts respectfully in writing. B is a bit more tricky, as the counterargument is an opposing argument but you want to refute it so your main argument gets stronger, not weaker.
Answer:
A. to respectfully address any doubts or objections to the claim
Why:
It's correct on Plato