The correct answer is A.
Gregorian chant is monophonic which means that it has a basic texture. It
consists only of melody and is not accompanied by a harmony. The same note is
produced from men and women and all notes are sung together. The Gregorian
chant is commonly used in churches and other religious congregations and was
first developed in 9th and 10th century in western and
central Europe. Pope St. Gregory the Great is credited for the chant.
