Tybalt is the son of Lady Capulets brother, which makes him Lady Capulets nephew and Juliets Cousin. He is related to to them.
The answer would be (A) again because in a essay you are stating your points and you have a structure on how to do it and it must be consistent throughout the whole essay or its going to be choppy and you wont get a good grade. hopefully that made sense. The other answers wouldn't make sense. So go with (A)