Based on the IRR of Projects S and L, their risk, and the WACC, the correct statement is b. If the WACC is 13%, Project S will have the higher NPV.
The IRR is rate of return that takes the NPV to zero. This means that if a project's WACC is less than IRR, then the NPV for that project will be less than 0.
Project L has an IRR of 12% which means that if the WACC is 13%, the NPV for this project will be negative.
Project S on the other hand would still have an IRR that is larger than the WACC and so would have a positive NPV.
In conclusion, option B is correct.
Find out more on IRR at https://brainly.com/question/7920964.