Answer:
d. upheld papal claims to supremacy over secular rulers
Explanation:
Unam Sanctam is the most famous papal document which was issued in 1302 which affirmed that the papal have supremacy over all human authorities.
The document defined it that the spiritual power rest upon the church and while the temporal power rests upon kings and soldiers.
Pope Boniface VIII issued the Unam Sanctam on November 18th, 1302.