The change in a firm's total cost from producing one more unit of a good or service is

During the decade of the 1920s, the U.S. economy

(a) was generally healthy and gave no indication of the troubles that lay ahead regarding the Great Depression. (b) was relatively stagnant in terms of growth of total output with small declines in agriculture and housing, which suggested that difficult times might lie ahead in the 1930s. (c) experienced actual declines in overall production levels, including agriculture and housing, which suggested that even more difficult times probably lay ahead. (d) experienced relatively rapid growth in overall output but in the late 1920s nevertheless showed weaknesses in certain sectors such as agriculture, housing and the financial sector, which suggested the possibility of difficult times ahead.

From the mid 1980s to the present, the United States

a. had only a small current account deficit. b. had a large capital account deficit, which in the balance of payments accounts was financed with a surplus in the current account, which in turn financed investment in excess of domestic saving. c. has had a large current account deficit, which in the balance of payments accounts was financed with a surplus in the capital account, that in turn financed investment in excess of domestic saving. d. None of the above