Answer:
A. ars nova.
Step-by-step explanation:
Guillaume de Machaut (1300 - 1377) was a French composer and poet born in Machaut, considered Ars Nova's greatest musician, a period that encompasses all music composed between the fourteenth and sixteenth centuries. Canon of the famous Reims cathedral, he was secretary of John of Luxembourg (1296-1346), king of Bohemia (1310-1346). His musical work is considered one of the high points of 14th century art. He was the author of lyrics, ballads, dances, motets and the famous Messe Notre Dame, the first polyphonic mass. Ars Nova's style is more expressive and refined, its rhythms more flexible and its polyphony more evolved.