The correct option is C well / good
Adverb of manner is used to tell the way or how something is done. Adverbs of manner are usually placed after the main verb or after the object. 'Well' is an adverb of manner which is often placed after the sentence's object or main verb. 'Paints' is the main verb in the given sentence. 'Good' is an adverb of positive degree. Thus, option C is the correct answer.