A new mother on the postpartum unit runs out of the room screaming that her newborn infant's crib is empty and the baby is missing. Which action should the nurse take first?

A. Determine if the newborn is in the nursery: This action directly addresses the immediate concern of the missing newborn and ensures prompt verification of the infant's location. B. Match ID bands of all infants and mothers on the unit: While important for ensuring proper identification, this action may take longer to complete and should follow the immediate concern of locating the newborn. C. Activate the lockdown procedure: This extreme measure should only be implemented if there is evidence of a security threat or if there is reason to believe that the newborn has been abducted. D. Ask the mother if any visitors were expected to arrive: While obtaining this information may be relevant for investigation purposes, it should not delay the immediate search for the newborn.