A $100 annuity means Oa. $100 is received each year for a certain number of years. Ob. $100 is received each year forever. Oc. $100 is received in a single year. Od. a person receives more than or less than $100, depending on the interest rate, for a certain number of years. O e. a person receives more than or less than $100, depending on the interest rate, until an upper limit is reached