Decision Rule on New Project Based on Marginal Cost of Capital

XYZ Corporation is considering a new project that will require a total investment of $5 million. The company currently has $2 million in existing equity and an additional $3 million is to be raised through new equity issuance, which will result in a dilution of current shareholders. Previous investors have expressed concerns regarding the expected returns. XYZ's weighted average cost of capital (WACC) is currently 10%, but given the additional equity issuance, the marginal cost of new equity has been assessed at 12% due to higher risk perceptions from investors.

If XYZ Corporation proceeds with the project, it will expect the project to generate a return of 15%. After evaluating the new capital structure, what will be the decision rule based on the marginal cost of capital (MCC) that XYZ should follow?