Answer:
A). Could not be heard above the voices in the hallway.
Step-by-step explanation:
A predicate is exemplified as the part of the sentence that states or asserts a description of the subject and consists of a verb and a description of the subject.
In the given question, the fragment that consists of a complete predicate is 'could not be heard above the voices in the hallway' as it includes a verb phrase 'could not be heard' along with the description 'above the voices' that asserts a complete description of the subject. Thus, option A is the correct answer as the other options fail to possess the characteristics of a complete predicate as mentioned above. Option B provides a reason while option C and D do not contain a verb.