Harry : Are those your books?
May : Some of these books are mine, and some are Maria's and Julia's and Sara's.
Harry : Which ones are Maria's?
May : Let's see. This red one is Maria's and the yellow one is also hers.
Harry : Which ones are Julia's?
May : The black one and the blue one are hers.
Harry : Which ones are Sara's?
May : The white one and the pink one are Sara's book.
Harry : So how many books do you totally have?
May : The rest is mine. It is six books.
Which books are Julia's?
The pink and yellow one.
The red and yellow one.
The white and blue.
The black and blue.