If potential output exceeds actual output, the aggregate demand curve shifts downward over time

In the economic way of thinking, which statement makes the most sense?

A) Costs determine prices. B) Prices determine costs. C) Costs determine demand. D) Demand determines supply.

In the above figure, what is total profit at the profit-maximizing point?

A) $14 B) $56 C) $42 D) $70