This year, a nation's long-run equilibrium real GDP and price level both increased. Which of the following combinations of factors might simultaneously account for both occurrences?
a. An isolated earthquake at the beginning of the year destroyed part of the nation's capital stock, and the nation's government significantly reduced its purchases of goods and services.
b. There was a technological improvement at the end of the previous year, and the quantity of money in circulation rose significantly during the year.
c. Labor productivity increased somewhat throughout the year, and consumers significantly increased their total planned purchases of goods and services.
d. The capital stock increased somewhat during the year, and the quantity of money in circulation declined considerably.