Parallel construction means that you

Ause the same grammatical construction in all similar headings throughout an outline.
Bbegin each paragraph of your essay in the same way.
Crepeat the first paragraph of your essay as the last paragraph.
Dgive both sides of the argument in your essay.

Verified Answer :

The correct answer is A. use the same grammatical construction in all similar headings throughout an outline.

This kind of a construction is also familiar as a parallelism or a parallel structure.

Answer;
B. Use of the same grammatical construction in all similar headings.

Explanation; 
Parallel construction means the same grammatical construction used repeatedly many times in the same text. It involves using elements in sentences that are grammatically similar or identical in structure sound, meaning, or meter. This style adds symmetry, effectiveness and balance to the written piece.