The clause fragment is option a. "Because the yard is so small!" A clause fragment is a group of words that is missing a subject or a verb and cannot stand alone as a complete sentence.
The correct answer is option a. Because the yard is so small! This is a clause fragment because it lacks a main subject or verb. A complete clause must have both a subject and a verb to form a complete thought. In this case, "Because the yard is so small" serves as a dependent clause, but it needs an independent clause to complete the thought. To identify a clause fragment, you can look for incomplete thoughts or sentences that are missing a subject or verb or do not express a complete idea.