When the NCLEX asks 'which client should the nurse see first,' work the airway first. Stridor, drooling, choking, or a swelling tongue beats almost any other finding.
Next, look at breathing — a respiratory rate under 10 or over 30, a falling SpO2, or new use of accessory muscles outranks most circulation problems.
Then circulation — a falling blood pressure, weak peripheral pulses, or new chest pain. Stable expected findings (post-op pain at 5/10, glucose 184) always lose to a true ABC threat.
If two clients both have an ABC issue, choose the one whose problem is most acute, unexpected, and reversible right now.