After Christianity received acceptance within the Roman Empire, churches were constructed above the catacombs and burial sites, which were all on the city's outskirts. What political reason might Constantine have had to commission churches on those sites?

A. To keep the Christian monuments out of the city proper and avoid displeasing the pagan populations 
B. To appeal to the Christian populations by recognizing the importance of their sacred sites 
C. To keep with the Edict of Milan, which dictated that churches should be constructed outside of the city proper 
D. To respond to the pagan populations' protests about allowing Christians in the city proper