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.
Naturalism is an abstract development which originates from authenticity, implying that it is endeavoring to pass on reasonable pictures, without the utilization of wonderful dialect and idealism. Unending song and great musical drama aren't scholarly developments, and sentimentalism is very inverse of naturalism, it underlines graceful dialect and idealism instead of authenticity.
