How does the Apostle Paul's appeal to Philemon regarding Onesimus challenge or subvert the social norms and legal structures concerning slavery in the Roman Empire?

A Paul directly condemns the institution of slavery and demands Philemon to immediately free all his slaves, setting a precedent for abolition. B Paul subtly undermines the societal acceptance of slavery by emphasizing Onesimus's value as a brother in Christ, advocating for reconciliation and potential manumission based on Christian love, while not explicitly denouncing the institution itself. C Paul reinforces the existing social hierarchy by instructing Onesimus to return to Philemon and continue serving him as a slave, thereby maintaining the status quo. D Paul offers a compromise by suggesting that Philemon should treat Onesimus with kindness but retain him as a slave, acknowledging the limitations of challenging Roman law directly.