Given a market wage of W*, what is the expression for the market quantity demanded of labour Nm? The vertical summation of all of the Nf curves, where Nf is the firm's quantity demanded of labour at W*. The product all of the values of Nf, where Nf is the firm's quantity demanded of labour at W*. The percent change in Nm divided by the percent change in the wage. It cannot be derived, as it has to be given. The sum of all of the values of Nf, where Nf is the firm's quantity demanded of labour at W*