There are three categories of cash flows: single cash flows, also referred to as "Iump sums," a stream of unequal cash flows, and annuities. Based on your understanding of annuities, answer the following questions. Which of the following statements about annuities are true? Check all that apply. When equal payments are made at the end of each period for a certain time period, they are treated as ordinary annuities. An ordinary annuity of equal time earns less interest than an annuity due. A perpetuity is a series of equal payments made at fixed intervals that continue infinitely and can be thought of as an infinite annuity. When equal payments are made at the end of each period for a certain time period, they are treated as an annuity due