When assessing the apical pulse, which of the following techniques is most accurate for obtaining the pulse rate?

Using a Doppler ultrasound device over the brachial artery.

Palpating the radial artery while counting beats for 30 seconds.

Using a stethoscope, auscultate at the second intercostal space, right midclavicular line.

Using a stethoscope, auscultate at the fifth intercostal space, left midclavicular line.