Internal rate of return is ratio in which a benefit cost equals 1 b benefit cost 1 c benefit cost 1 d none of these?

The internal rate of return (IRR) is the discount rate at which the net present value (NPV) of a project's cash flows equals zero. This means that the benefit-cost ratio is equal to 1, indicating that the project's benefits are equal to its costs. Therefore, the correct answer is a) benefit cost equals 1.