How are national debt and deficit related?

a. a deficit is the money the government owes the states.

b. a deficit is the sum of national debts.

c. the national debt is an accumulation of deficits.

d. the national debt is the sum of state deficits.,

The national debt and deficit is related in the aspect that the national debt is an accumulation of the deficits. Deficits are the excess of the government's expenses over the government's revenues or receipts. To cover up for these deficits, the government would need to incur a national debt for the sustainability of the country.