While many know of Paul's missionary journeys, what was a significant impact of the letter to Philemon in the New Testament?

A It established a formal system for the manumission of slaves within the early Christian community. B It provided a legal framework for resolving disputes between Christians and non-Christians in the Roman Empire. C It exemplified the call for reconciliation and brotherhood, challenging social hierarchies by imploring Philemon to receive Onesimus, his formerly enslaved person, as a brother in Christ. D It outlined the qualifications and responsibilities for becoming a church leader in the first century.