Dora is keeping track of the number of books she has read during the current school year. She has already read 4 books.
Which equation shows the total number of books, y, Dora will have read by the end of the school year?
A. y = 4x, where x represents the number of books Dora has already read
B. y = x + 4, where x represents the number of books Dora has already read
C. y = 4x, where x represents the number of books Dora reads between now and the end of the year
D. y = x + 4, where x represents the number of books Dora reads between now and the end of the year