25. I gave both Ria and Sylvie a piece of paper. Each piece of paper had a positive integer written on it. I then told them that the two integers were consecutive. Ria said "I don't know your number". Then Sylvie said "I don't know your number". Then Ria said "Ah, I now know your number". Which of these could be the integer on Ria's piece of paper?
A 1
B 2
C 4
D 7
E 11