A is correct answer because it tells both sides of the war equally
Assuming that in the last option 'whichever melody you create' is underlined, the correct answer is that one, the last sentence. Because this is the only sentence in which 'to' is used as a preposition, in 2 and 3 there are no prepositions, and in 1 'to' is a part of an infinitive phrase.
Answer:
To organize the text and to make the text easier to read
We use subheadings to give readers a sense of what they are reading, not to make them think the work is legit, and not to introduce new information or point out important facts. We want readers to know what is coming, and what they are going to read so we don't waste their time