A risk associated with project and way considered by well diversified stockholder is classified as

Well-diversified stockholders are not concerned with expected risk, as this risk is diversified away by holding a portfolio of stocks. They are also not concerned with industry risk, as this risk can be diversified away by holding stocks from different industries. Returning risk is not a valid measure of risk.

Beta risk is the only measure of risk that is relevant to well-diversified stockholders. This is because beta risk is the only risk that cannot be diversified away.