\begin{gather*} A = \{\frac{3}{5}, 2, \frac{7}{2}, 4, \frac{15}{3}, 8\} \\ B = \{\frac{3}{5}, \frac{5}{3}, 4, 8\} \end{gather*} If n is a member of both set A and set B above, which of the following must be true? I. n is an integer II. 5n is an integer III. n = 5
(A)II only (B)III only (C)I and II only (D)I and III only (E)I, II, and III
A