When Drawn Against the Current Real Wage, the Labour Demand

When drawn against the current real wage, the labour demand curve is

A) upward sloping because the marginal product of labour rises with the quantity of labour employed.
B) upward sloping because the marginal product of labour declines with the quantity of labour employed.
C) downward sloping because the marginal product of labour rises with the quantity of labour employed.
D) downward sloping because the marginal product of labour declines with the quantity of labour employed.
E) downward sloping because the marginal product of labour is constant.