HELP PLEASE! Help me with at least one of them! (Subject is Music)

1. Which person or group brought polyphonic music into the Christian church?

a) Hildegard von Bergen
b) the Notre Dame School
c) Pope Gregory
d) Guillaume de Machaut

2. Who created a songbook of liturgical melodies and a singing school?

a) Hildegard von Bergen
b) Guido d'Arezzo
c) Guillaume de Machaut
d) Pope Gregory

3. Which phrase best describes a motet?

a) a composition with original melodies composed with secular texts
b) a secular form of music consisting of three to fix voices, often in Italian
c) standardized chant repertoire of the Roman Catholic Church
d) a specific set of melodies for singing Roman Catholic religious texts