A series of equal cash flows at fixed intervals is termed a (n)

A) present value index
B) price-level index
C) net cash flow
D) annuity

An annuity is a series of equal cash flows that occur at fixed intervals. Therefore, option D is the correct choice. Option A (present value index) is not related to a series of equal cash flows, option B (price-level index) does not involve cash flows, and option C (net cash flow) does not necessarily involve equal cash flows.