A nurse has just received hand-off communication at the start of their shift. After reviewing each client's status, which of the following clients should the nurse see first?

A 3-year-old toddler who aspirated several sunflower seeds and continues to cough with an O2 saturation of 91%.

A 6 year old child admitted with asthma exacerbation who used a rescue inhaler 16 hours ago.

A 15-year-old adolescent who had a laparoscopic appendectomy 30 hours ago, rates their pain a 3 on a scale of 1 to 10, and is preparing for discharge this morning.

An 18-month-old admitted for dehydration 2 days ago who has had six wet diapers in the last 24 hours and ate 90% of their meals.