The internal rate of return is the: discount rate that causes a project’s aftertax income to equal zero. discount rate that results in a zero net present value for the project. discount rate that results in a net present value equal to the project's initial cost. rate of return required by the project's investors. project's current market rate of return.

The IRR is the discount rate that results in a zero net present value for the project

Explanation:

discount rate that results in a zero net present value for the project

This means the IRR is the maximun yield of a project, a rate below IRR will create a positive NPV

and a rate above the IRR will do a negative NPV

answer; i believe the correct answer is radioactive decay);