While one requires oxygen and one does ______ blank and anaerobic respiration are both forms of

Choice C is the best answer. A comma is the appropriate way to link the dependent clause “While...not” and the independent clause that follows.

Choice A is incorrect. This choice creates a run-on sentence error. “While...not” is a dependent clause, which must be separated from the independent clause that follows with some sort of punctuation. Choice B is incorrect. This choice creates a sentence fragment. “While one requires oxygen and one does not” isn’t an independent clause, so it can’t stand alone as a complete sentence. Choice D is incorrect. This choice creates a punctuation error. “While one requires oxygen and one does not” isn’t an independent clause, so it can’t be linked to the clause that follows with a semicolon.