My father regrets taking up smoking. He cant give it up  now.

A. Regretful as my father is, there might be a chance for him to stop smoking.

B. My father can't give up smoking now and feels regret about it.

C. My father regrets having taken up smoking because he's not able to give it up now.

D. My father wishes he hadn't taken up smoking since he can't cut down it now.