A nurse is collecting data from a 5-month-old infant who is postoperative following umbilical hernia repair. Which of the following measures should the nurse use to evaluate the infant's pain level?

A. The FLACC pain rating scale is appropriate for infants and young children, assessing pain based on Face, Legs, Activity, Cry, and Consolability, making it suitable for a 5-month-old infant. B. The COMFORT pain rating scale is generally used for children who are unable to communicate their pain, typically in older children or adolescents, and is less suitable for this age group. C. The FACES pain rating scale is designed for children aged 3 and older who can identify facial expressions but is not appropriate for a 5-month-old infant. D. The CRIES pain rating scale is also used for infants but is more specific to neonates (0-6 months) and measures crying, oxygen requirement, increased vital signs, and facial expressions, making it less applicable than the FLACC scale for this specific postoperative context.