No. it can be considered a sentence.
The correct answer is D. It cannot stand alone as a sentence.
Explanation
Dependent clauses are incomplete sentences composed of a subject and a verb and are characterized by not expressing a complete idea. Dependent clauses must be related to an independent clause to make sense of it. The independent clauses are sentences composed of a subject and a verb, in addition, unlike the dependent clauses, they express a complete idea. Therefore, the correct answer is D. It cannot stand alone as a sentence.
