The Production Function Is F(L, M)= 4L^1/2 M^1/2, Where L

the production function is f(L, M) = 4L^1/2 M^1/2, where L is the number of units of labor and M is the number of machines used.If the cost of labor is $49 per unit and the cost of machines is $36 per unit, then the total cost of producing 4 units of output will be

A) $84.
B) $170.
C) $144.
D) $168.
E) None of the above.