Which of the following statements is CORRECT? Select one: a. If the interest rate is positive, then the present value of an annuity due will be less than the present value of an ordinary annuity. O b. If Joe borrowed $10,000 at 10% per year and promised to pay it back in equal annual installments at the end of each of the next 5 years, then his yearly payment will be $2,100. c. To evaluate or compare investment proposals, we must bring the value of all cash flows to a common date. d. The present value of an annuity increases as the discount rate increases