Assume that there has been an increase in the marginal productivity of construction workers building new housing

The correct answer to the given question is option d. Supply of new housing will rise, leading to an increase in the equilibrium quantity and a decrease in the price of new housing.

The marginal productivity for a firm is defined as the quantity of output produced by one unit of additional input resource such as labor. An increase in the marginal productivity of construction workers building new housing implies that the overall supply of the new housing in the market will increase. Thus, as the demand of housing does not increase in line with its supply, the prices of the new houses will fall which will lead to increase in the equilibrium quantity such that the quantity demanded is now equal to the increased supply.