The average (arithmetic mean) of the numbers v, w, x, y, and z is j, and the average of the numbers x, y, and z is k. What is the average of v and w in terms of j and k ?
A. (j – k) / 2
B. (j + k) / 2
C. (5j – 3k) / 3
D. (5j – 3k) / 2
E. (5j – k) / 2