Final answer:
Guillaume de Machaut was the first known composer to write music with more than two voices, which was a significant development in the evolution of polyphony during the medieval Ars nova period.
Correct option is a) Guillaume de Machaut
Step-by-step explanation:
The first known composer to write music with more than two voices is Guillaume de Machaut. Machaut, a significant figure from the medieval period, contributed greatly to the development of polyphony and the Ars nova. This movement of music signified the transition from monophonic music, such as Gregorian chant, to intricate polyphonic textures. Polyphony became increasingly elaborate during the fourteenth century, and by the Renaissance, it developed further as composers explored harmonies based on thirds, which had previously been considered dissonances.
In contrast to Machaut's time, the later composer Hildegard of Bingen is recognized mostly for her monophonic liturgical works, and while Palestrina was a master of polyphonic choral music in the High Renaissance, his work came later than Machaut's. Lastly, although Ludwig van Beethoven is a notable figure who bridged the Classical and Romantic eras, he wrote music far after the period when composers began creating polyphonic works.