Final answer:
A client with an arrhythmia is a candidate for apical pulse measurement over radial pulse due to the irregular nature of the heartbeat, allowing for more accurate assessment of heartbeats.
Step-by-step explanation:
The client who meets the criteria for selection of the apical site for assessment of the pulse rather than a radial pulse is a client with an arrhythmia. Measurement at the apical site provides a more accurate representation of heartbeats when the heartbeat is irregular, as in the case of arrhythmias. Apical pulse assessment involves auscultation using a stethoscope placed at the apex of the heart, which can detect beats that may not be palpable at peripheral sites like the wrist when there is an arrhythmia.