Elliot has a total of 26 books. He has 12 more fiction books than nonfiction books. Let x represent the number of fiction books and y represent the number of nonfiction books. Which system of linear equations represents the situation?

a x + y = 26 and x + y = 12

bx + y = 26 and x – y = 12

cx + y = 26 and –x + y = 12

dx – y = 26 and x + y = 12