The answer is D.) it creates humor and surprise that the once enemies fell in love and marry
1) D , Have competed
2) B , Their
I would say your answer is creating tension. the rest dont seem to work since refuting a counterclaim will make the argument weaker, but it will help the story, not bring it down. it obviously doesnt make the argument stonger, and the main purpose is for the audience to see both sides. so my answer would be creating tension. hope this helps