D. That all aspects of the piece should work together to create a certain effect
To create a "unity of effect" on the reader, it should have a certain effect on the reader. Like a really sad and depressing book should not exactly make the reader sad, but to feel the parts of the book that spoke out to the reader.
It means don't be expecting much. When people hold their breath, they are waiting for something to happen. WHen people give the advice of dont hold your breath, they are saying taht there isn't anything going to happen
The speaker goes outside. A.
<span>"Excuse me…'scuse me…sorry!" He gets up and heads for the exit. He walks outside and, what a difference! <------ From "When I heard the Learn'd Astronomer."
</span>
I hope this helps. C: