Final answer:
The underlined portion 'before i could utter a single syllable' lacks a main subject and verb, thus it is an incomplete thought. It should be connected to the complete sentence that follows it for clarity and coherence. The correct answer is option B: incomplete.
Step-by-step explanation:
Identifying whether a part of a sentence is a complete thought or an incomplete thought is essential in ensuring sentence clarity and coherence. The underlined phrase in question, 'before i could utter a single syllable', sets a time-dependent context but does not form a complete thought by itself. It lacks a main subject and verb and therefore cannot stand alone as a sentence. However, the second part of the sentence, 'Devon stuffed the entire sandwich into his mouth', is a complete thought because it has a subject ('Devon') and a verb ('stuffed'), and it expresses a complete idea.
To determine if a sentence fragment can stand alone, it should be able to answer the questions who or what is the subject and what is the action or predicate. Interrupting clauses like the one presented should not be separated from their companion sentence if they cannot answer these questions on their own. Thus, the underlined portion needs to be connected to a main clause to avoid being a sentence fragment.
The correct way to correct a sentence fragment is to ensure it is connected to a complete sentence. Either by rewriting it to include a subject and predicate of its own or attaching it to a related complete sentence.
In light of this, the underlined portion of the sentence is an incomplete thought. The final answer to whether the underlined portion of the sentence is a complete or incomplete thought is option B: incomplete.