Final answer:
Option B, 'Nighttime leg cramps frequently occur in calf muscles,' is a complete sentence as it contains both a subject and a predicate and expresses a complete thought.
Step-by-step explanation:
The question asks which of the given options is a complete sentence. A complete sentence must have at least a subject and a predicate (a verb), and it must express a complete thought. Among the given options,
- Option A: 'The flight attendant on our return trip from Phoenix.' This is not a complete sentence because it lacks a predicate. It tells us about 'The flight attendant' (the subject) but does not include an action or state of being.
- Option B: 'Nighttime leg cramps frequently occur in calf muscles.' This is a complete sentence because it has a subject ('Nighttime leg cramps') and a predicate ('frequently occur in calf muscles'), and it expresses a complete thought.
Therefore, Option B is the complete sentence.