Answer:
A) The equilibrium price will increase, and the equilibrium quantity will decrease.
Explanation:
Since the cost of building materials have increased, equilibrium price of new houses will increase, however, equilibrium quantity of new houses will reduce. According to the law of supply and demand, unless a product is inelastic, increase in price results in decrease in demand. Thus with the increase in the cost of new houses, will bring about a decrease in the quantity of new houses.