Which of the following statements is true regarding the national debt?

a. the national debt is the total revenue earned by the government at the end of every financial year.
b. the terms budget deficit and national debt are synonymous with each other.
c. interest owed on funds borrowed by the government is the only element of the national debt.
d. the national debt decreases with every budget deficit that the government runs.
e. the government's future spending ability is affected by an increase in national debt.