The correct option is B Repartee
'Witty, clever retort' is Option B, Repartee. Option A, 'Sarcasm' is the use of remarks in order to hurt someone's feelings. Option C, 'Platitude' is a statement that may be true but is boring because it has been said many times before. Option D, 'Invective' means abusive or insulting. Thus, options A, C and D are incorrect and the correct word for the given phrase is Option B, Repartee.