The productivity of a country is given by the function f(x,y)= 32x^0.3y^0.7 , where x represents the utilization of labor and y represents the utilization of capital. If the company uses 5000 units of labor and 3000 units of capital, Find the marginal productivity of labor.
A. 32.0 units per unit increase in labor expenditure.
B. 27.7 units per unit increase in labor expenditure.
C. 6.7 units per unit increase in labor expenditure.
D. 13.7 units per unit increase in labor expenditure.
E. Not listed