C. the same grammatical construction is used in all similar headings throughout an outline, would be the answer
The correct answer is reading.
Although you may be lead to believe that the correct answer is poem, because of its clear distinction from novels when it comes to structure, the actual correct answer is reading. Reading can refer to reading novels, poems, and plays alike - covering various structures and genres. And there are poems in prose from, as well as novels in poetic form - so poem is incorrect.
I think that the correct answer is D.
