A 9-month-old patient is unresponsive in a crib.

Comprehensive and Detailed Explanation (Based on NREMT standards):

In pediatric patients, NREMT guidelines require EMTs to check a pulse before initiating CPR when the patient is unresponsive and not breathing. For infants, the appropriate pulse check site is the brachial artery, assessed for no more than 10 seconds.

Option D is correct because determining whether a pulse is present guides whether rescue breathing or full CPR is required.

Option B is only appropriate if a pulse is present.

Option C is indicated only if no pulse is found or if the heart rate is below 60 with signs of poor perfusion.

Option A delays critical resuscitative care.

NREMT stresses strict adherence to pediatric resuscitation sequences to ensure appropriate and timely intervention.