The best one would be A or B. I think the best one would be A because it makes more sense, and since you are writing a summary of a legend titled like this, yes, its the best answer to use! But im sorry if im wrong, but i hope this helped! :D
A. Everything turned out for the best, after all. "Everything turned out for the best," is the main part of the sentence and" after all," is an addition to the main part.