Does this graph represent a function?

(A) The graph does not represent a function, because the y-value 2 has two x-values

(B) The graph does represent a function, because it passes the vertical line test.

(C) The graph does not represent a function, because it fails the vertical line test.

(D) The graph does represent a function, because 3 appears as both an x-value and a y-value.