Equations for C, I, G, and NX are given below. If the equilibrium level of GDP is $32,000, what is the marginal propensity to consume? C = 5,000 + (MPC) Y 1 = 1,500 G = 2,000 NX = -500 Select one: O a. 0.9 O b. 0.67 O C. 0.8 O d. 0.75