The demand for good X is estimated to be $Q_x^d = 10,000 - 4P_X + 5P_Y + 2M + A_X$, where $P_X$ is the price of X, $P_Y$ is the price of good Y, M is income, and $A_X$ is the amount of advertising on X. Suppose the present price of good X is $50, $P_Y = $100$, $M = $25,000$, and $A_X = 1,000$ units. Based on this information, the income elasticity of good X is
Multiple Choice
0.816.
0.082.
8.157.
0.008.