A rectangle on a coordinate plane has vertices Q(-1, 1), R(6, 1), S(6, Negative 8), and T(-1, -8). What are the dimensions of the rectangle?
A) The base is 6 and the height is 9.
B) The base is 9 and the height is 6.
C) The base is 7 and the height is 9.
D) The base is 9 and the height is 7.