<span>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.</span>
The correct answer should be A. naturalism.
Naturalism is a literary movement which comes from realism, meaning that it is trying to convey realistic images, without the use of poetic language and escapism. Endless melody and grand opera aren't literary movements, and romanticism is quite opposite of naturalism - it emphasizes poetic language and escapism rather than realism.
D is the answer for this question