Why did Leoninus compose his organa?

A) no one knows
B) because Pope Calixtus II desired a repertoire of polyphony for pilgrims to sing while on pilgrimage to Santiago de Compostela
C) for the entertainment and edification of the "literati," the students and masters who lived at the cathedral and university
D) to enhance the liturgical splendor on important days in the church year

D