A mother needs to put her childrens needs ahead of her own
The correct answer for the given statement above would be option C. A clause used as the object of a preposition is called a noun clause. The object of the preposition will always be a noun. Therefore, the only clause that is also used as the object of a preposition is only the noun clause.
The answer is A. She is making a claim that is still arguable but a stated fact.
I believe the answer would be A ^^