In the book of Philemon, what is the deeper theological implication of Paul's appeal to Philemon regarding Onesimus, beyond a simple request for forgiveness and restoration?

A Paul is primarily concerned with maintaining the social hierarchy of the Roman Empire by reinforcing Philemon's authority as a slave owner. B Paul subtly undermines the institution of slavery by advocating for Onesimus to be received as a brother in Christ, challenging the prevailing social order and hinting at the equality of believers. C Paul is solely focused on avoiding conflict with Roman authorities by promoting obedience to slave owners. D Paul's appeal is merely a strategic maneuver to gain favor with Philemon and secure financial support for his missionary journeys.