If x < y < z, z = ky, x = 0, and the average of the numbers x, y, and z is 3 times the median, what is the value of k?
(A) 2
(B) 3
(C) 5.5
(D) 6
(E) 8
(A) 2
(B) 3
(C) 5.5
(D) 6
(E) 8