Answer:
Gregorian Chant exhibits all except C. polyphony
Explanation:
Chant is monophony (one single line voice)
polyphony is more than one line together
The correct answer is D. a balanced and harmonious composition
Trumpets at this time horns as a general term appeared in earliest as forms of battle communication. These horns had not valves or button and could only produce root pitches. The valves added an extension to the instruments note capabilities however the construction of the piping has stayed mostly the same with the length of tubing associated with the pitch or key to which it is played in