Final answer:
The subject of this question is Health, and the correct answer is C. Relying on observation and documentation is sufficient for pain assessment.
Step-by-step explanation:
The subject of this question is Health. The question is discussing the importance of obtaining complete information from the family during pain assessment and the alternative methods that can be used if this information is not available. The correct answer is C. Relying on observation and documentation is sufficient for pain assessment because observation of nonverbal behavior and careful documentation can help determine pain and relief patterns when complete information is not obtained from the family.