For the Regression Equation Q = 100 - 10X

For the regression equation Q = 100 - 10X + 0.25X²,which of the following statements is true?

A) X² is the more important variable because it is positive.
B) When X decreases by one unit,Q decreases by 10 units.
C) When X increases by 10 units,Q decreases by 1 unit.
D) The change in Q associated with a one unit increase in X depends on the initial level of X.