In short-run equilibrium in a perfectly competitive market, firms always make zero economic profit

In the figure above, if the price is $8 a unit, is there a shortage or surplus and what is the amount of any shortage or surplus? What is the equilibrium price and quantity?

What will be an ideal response?

In Figure 3-4 above, the shift from Ap0 to Ap1 could have been caused by a ________ in T of ________

A) fall, 300 B) fall, 180 C) fall, 500 D) rise, 300 E) rise, 500