What did edgar allan poe mean when he said a literary piece must create a "unity of effect" on a reader?

a. that the effect of all books of one genre be unified by one theme
b. that every character in the piece will be unified by a common dark secret
c. that everyone reading the piece will be unified by an experience
d. that all aspects of the piece should work together to create a certain effect

I would say that by unity of effect Edgar Allan Poe meant that all aspects of the piece should work together to create a certain effect on a reader. The correct answer is D.

Explanation:

To create a unity of effect I understand is for the author, any author, to write a work that is a whole and not pieces of different things. By a whole I mean a unity, a piece that contains details that complement each other with the object of telling a story. It is obvious that each reader will feel different things when reading because it is in our nature to be different and to receive things based on our own experiences, but the objective of the piece must be clear, and all of the details inside the story must create a unity, they must be complementary, pieces of the same objective. That's why I think he meant that a piece should work together to create a certain effect on the reader.

the answer is b. my dude

i would say the correct answer is not concrete.