Transactions involving items produced in the past, such as the sale of a 5-year-old automobile by a used car dealership or the purchase of an antique rocking chair by a person at a yard sale, are
a. included in current gdp because gdp measures the value of all goods and services sold in the current year.
b. included in current gdp but valued at their original prices.
c. not included in current gdp because it is difficult to determine their value.
d. not included in current gdp because gdp only measures the value of goods and services produced in the current year.