Which of the following is true regarding IRR?

A.
IRR is a constrained optimization method.

B.
IRR assumes reinvestment at the cost of capital.

C.
IRR is the discount rate when NPV is greater than zero.

D.
IRR is the discount rate when NPV is equal to zero.

Explanation:
IRR assumes reinvestment at the IRR rate and is the discount rate when NPV is equal to zero.