The function M(x) = 5x2 - 160x + 6179 models the number of miles, in millions, US passengers travel on a train for the period of 1970 to 2000,
where x is the number of years since 1970.
Part A: Which equivalent form reveals the minimum number of miles, in
millions, US passengers traveled on a train for the period of 1970 to
2000?

A. M(x) = 5x(x - 32) + 6179
B. M(x) = 5(x - 16)2 + 4899
C. M(x) = 5(x - 32) + 1059
D. M(x) = 5(x - 16)2 + 6435