Suppose That the Production Function for the Economy Is Y

Suppose that the production function for the economy is Y = AK⁰.²ᴸ⁰.⁸.If the capital stock = 40 000,the quantity of labour = 10 000,and the efficiency index = 1,the marginal product of labour is

A) $0.80.
B) $1.06.
C) $1.32.
D) $5.26.