Answer:
b) No changes need to be made.
Explanation:
A complete sentence is a sentence that begins with a capital letter, ends with a mark, namely, a period, a question mark or an exclamation point, contains at least a subject and a verb and expresses a complete idea on its own.
So, "No one but Marella was in the car when the accident occurred" is a complete sentence because it begins with a capital letter, ends with a period, has a subject: "No one but Marella", a verb: "was" and complements, and it expresses a complete thought or idea on its own, meaning that it is not missing any word or phrase. Therefore, no changes need to be made in this sentence.
