For a typical capital investment project, a company needs to know its exact cost of capital in order to do calculate NPV. However an exact cost of capital is not needed for an IRR evaluation of the same project. What is the reason for this?

		The decision rule for IRR is reversed, so the cost of capital is not relevant for evaluating projects.
		A precise discount rate is needed to work out NPV, whereas with IRR an evaluation can be performed as long as an estimate or range of the cost of capital is available.
		An exact discount rate is needed to work out the correct NPV, whereas IRR does not incorporate time value of money, so the cost of capital is not needed.
		There is the possibility of multiple rates of return with IRR, so an exact cost of capital is not needed to do an evaluation.