Given the Demand Function Q_X = 5,000 - 250P_X +120P_Y

Given the demand function Q_X = 5,000 - 250P_X +120P_Y +.04I where
P_Y = $50.00 and I = $60,000. When the price of good X is increased from $30.00 to $40.00, what is the arc price elasticity of demand for good X over this range?

A) 2.88
B) -1.88
C) -2.995
D) 2.995
E) none of the above