Answer:
A) Rightward shift of the supply curve. When a company is able to produce its goods at a lower cost, the whole supply curve sill shift to the right. This can be accomplished through a new technology or a decrease in the price of inputs.
B) On the short run, the quantity demanded of paint will increase, since a better product usually means higher demand, so the demand curve will shift to the right. But on the long run, the quantity demanded for the product will decrease since the customers will not need to paint their houses as often as before, shifting the demand curve to the left.
C) This will shift the demand curve to the right, increasing the quantity demanded at every price level.
D) This will definitely reduce the quantity supplied and shift the supply curve to the left. It has a similar effect to a cost increase. This shift will last until the factories start producing again.