Final answer:
To assess an infant's pulse, the nurse should place their fingers on the brachial artery in the upper arm.
Step-by-step explanation:
To assess an infant's pulse, the nurse should place their fingers on the brachial artery in the upper arm. This is one of the common sites to find a pulse in infants. Other sites include the radial artery in the wrist, the femoral artery in the thigh, and the carotid artery in the neck.