When should firms follow "the Big-U" in their calculation of a project-specific WACC?

When the new project differs from the average project of the firm in terms of risk

When the new project differs in its financing (debt and equity weights) from the firm's overall debt and equity [i.e. capital structure] weights

When the new project differs in its financing (debt and equity weights) from the pure plays' average debt and equity [i.e. capital structure] weights

All of the above