Hi can you guys explain the manual as well as financial calculator solution?

16) Charlie Stone wants to retire in 30 years, and he wants to have an annuity of $1,000 a year for 20 years after retirement. Charlie wants to receive the first annuity payment at the end of the 30th year. Using an interest rate of 1 retirement annuity (round to the nearest $10)? A) $490 B) $570 C) $500 D) $540