Final answer:
The radial artery, located at the wrist, is the artery most frequently used for measuring heart rate due to its accessibility and ease of palpation.
Step-by-step explanation:
The artery most frequently used to measure heart rate because it is accessible and easily palpated is the radial artery. The radial artery is located at the wrist and is favored for its superficial position, making it easier to find and use for pulse measurement. Other common sites for pulse measurement include the carotid artery in the neck, brachial arteries in the upper arm, and femoral arteries in the thigh, among others. However, for convenience and ease, the radial artery remains the primary site used in most situations.