The element necessary to complete the sentence above is D) independent clause.
You already have a subject (I) and a predicate (save), so these two are not needed, nor is a prepositional phrase. But you need an independent clause, because this is a dependent clause which cannot stand on its own. For example:
If I save enough money, <em>I will buy a car. </em>
Not exactly sure what the Clean Verbatim Style Guide is, but i think the one with the correct grammar and such would be B
Explanation:
So hopefully b helps
