According to the Apostle Paul's teachings, particularly in Romans, what is the primary purpose of the Law after the coming of Christ?

A To continue to provide a means of justification for those who diligently follow its precepts. B To serve as a guide for believers in discerning God's will in their daily lives. C To demonstrate humanity's universal sinfulness and need for grace. D To be entirely disregarded as obsolete and irrelevant for Christians.