M(r, s, t) denotes the average (arithmetic mean) of r, s, and t, and M (x, y) denotes the average of x and y. Column A Column B M (70, 80, 90) M (x, 90) where x = M (70, 80)
A.
if the quantity in Column A is greater
B.
if the quantity in Column B is greater
C.
if the two quantity are equal
D.
if the relationship cannot be determined from the information given