The correct option is A 'You Cannot Please Everyone'
Though the passage centers around a miller, his son and their ass, it illustrates how one cannot please every one. By listening to the passerby first, then the old man and then another man; all of whom either commented on no one riding the ass, or the son riding the ass or the miller riding the ass; the miller and his son ultimately lost their ass. So, in this context the best subtitle from the given choices is option C- "You Cannot Please Everyone".