Although GDP is a reasonably good measure of a nation's output, it does not necessarily include all transactions and production for that nation. Which of the following scenarios are either not accounted for or measured inaccurately by either the income or the expenditure methods of calculating GDP for the United States?
a. The value of babysitting services, when the babysitter is paid in cash and the transaction isn't reported to the government
b. The variety of goods available to consumers
c. Expenditures on federal highways
d. The costs of overfishing and other overly intensive uses of resources
