Five books are arranged on a shelf: Book A is to the left of Book B, Book C is to the right of Book A, and Book D is to the left of Book E. What is the possible order of the books?
A, B, C, D, and E are five friends who are standing in a line. A is standing to the left of B but to the right of C. D is standing at one of the ends. E is standing to the right of B. What is the order of the friends from left to right?