If the market price is $40 in a perfectly competitive market, the marginal revenue from selling the fifth unit is

When a foreign investor buys a bond issued in the United States,

A) the balance on the financial account increases. B) the balance of trade increases. C) the balance on the current account increases. D) the balance on the capital account increases.

In a perfectly competitive market industry, firm's prices are equal to

a. Average revenue b. Marginal revenue c. Both a and b d. None of the above