Final answer:
The child who requires priority assessment by the nurse is the preschool-age child with tetralogy of Fallot (ToF) who presents with finger clubbing and irritability when awake.
Step-by-step explanation:
The child who requires priority assessment by the nurse is the preschool-age child with tetralogy of Fallot (ToF) who presents with finger clubbing and irritability when awake. Finger clubbing is a sign of chronic hypoxia and indicates inadequate oxygenation of the blood. This child may be experiencing a decrease in oxygen levels, which requires immediate intervention and assessment by the nurse.