9.) If the effective annual interest rate is i, which of the following is the present value of a perpetuity immediate under which each of the first five annual payments is 1, each the next five is 2, each of the next five is 3, and so on, with payments increasing five years? Explain your answer. D) 1 51 10 A varying immediate annuity with a term of 2n years has a first payment equal to 1. Thereafter payments increase by 1 each year until they reach n at the end of n years. Payments remain at n for year n +1 and then decrease by 1 each year, with a final payment of 1 at the end of 2n years. Derive an expression for the present value of this annuity. (A) a1-F) (E) ant + Multiple Choice: (B) and + ) (C) and- (D) and+9)