I believe the compositional styles matched with characteristics are:
a. Organum: a composition of two or more voices, one of
which is based on a previously existing chant melody.
Organum represents an early type of polyphonic music based on plainsong. In
contrast to Gregorian chant, organum has an accompaniment.
b. Gregorian chant: monophonic melodies compiled by a
certain pope.
This chant represent the central tradition of Western plainchant. It is a unaccompanied
sacred song of the Roman Catholic Church.
c. Polyphony: any composition using two or more independent
voices.
The polyphony is musical texture that combines melodic, rhythmic, and harmonic
aspects of a musical composition.
