How does the procedure for taking a pulse rate on an infant differ from an adult?

The correct answer is B: The apical pulse method is used on infants. This method involves placing a stethoscope in the fifth intercostal space, mid-clavicular line, and counting the beats for a full minute. It is a preferred method for infants due to their small size and the difficulty in palpating peripheral pulses accurately. Choices A, C, and D are incorrect. Choice A is incorrect as pulse rates are indeed taken on infants, albeit using a different method. Choice C is incorrect as a sphygmomanometer is typically used for measuring blood pressure, not pulse rates. Choice D is incorrect as pulse rates on infants are usually taken apically in the fifth intercostal space, not the third.