In the parable of the Unjust Steward (Luke 16:1-13), what is the primary lesson Jesus intends to convey regarding the use of 'worldly wealth' (mammon)?

A That it is inherently evil and should be avoided by believers. B That it should be used shrewdly, like the steward, to secure a future reward, even if it involves dishonesty. C That it should be used wisely and generously to serve God and others, demonstrating trustworthiness in both small and large matters. D That it should be accumulated and invested to generate more wealth for the kingdom of God.