Good question. I think it'd be a knife edge with the possibility of putting Nadal to the sword in Paris would making it a difficult decision for him. I think the other elements wouldn't carry much weight for him however and in the end the lure of two majors would win the day. He's only playing against the history books now and the former would be the more resounding entires on that score. Option B would be sweet but is more a personal pride and ego list which I think he would decline.
“There is no best. There is just the discussion of who is best. Federer, he will always be in the first part of such a discussion.” Rino Tommasi