Can you guess who wrote this?

Therefore although Peter, Paul, and the other apostles were indeed children of God, righteous according to the Law, and, finally, even ministers of Christ, they were not declared righteous in the sight of God on this account. For if you bind all these together into one bundle – the law, its works and righteousness, circumcision, adoption, the covenants, the promises, the apostolate, etc. – still Christian righteousness does not come through these; for none of these is Christ.

A. E.P. Sanders

B. Martin Luther

C. Augustine

D. W.D. Davies