Final answer:
The normal RR and HR for a 3-6 month old as defined by the ALS guidelines are a respiratory rate of 30-60 breaths per minute and a heart rate of 100-190 bpm, aligning with Option C.
Step-by-step explanation:
The Advanced Life Support (ALS) guidelines define normal vital signs for age-specific groups. For infants aged 3-6 months, the normal respiratory rate (RR) is between 30 and 60 breaths per minute, and the normal heart rate (HR) at rest can be expected to be higher than that of adults, given that newborn's resting HRs can be around 120 beats per minute (bpm) and it gradually decreases with age. However, the maximum HR can reach a rate of 200-220 bpm in extreme cases.
Considering the given options, the most accurate for the normal RR and HR for a 3-6 month old would be Option C: RR: 30-60, HR: 100-190. This range accounts for the expected physiologic parameters in this age group, where heart rate is typically higher than in older children and adults, and respiratory rate gradually decreases as the child approaches adolescence.