The answer I believe would be b
The correct answer is to nullify the Black Codes.
The correct answer is letter D.
The Tetrarchs since the late Middle Ages, the group has been set on the facade of St. Mark's Basilica, in Venice, Italy. It was probably originally part of the decorations of the Philadelphia, a public square in Constantinople, but it would have been removed by the Knights of the Fourth Crusade and taken to the Republic of Venice.
Aaron's priesthood was tainted with things that God said they shouldn't do, like ripping people off, etc.
Melchizedek, on the other hand, was known as a 'just priest'
this is why Christ's priesthood was after the order of Melchizedek
hope this helps :D