Which statement best differentiates H-Wave from TENS based on the described mechanisms?

• A. H-Wave uses distinct low- and high-frequency modes with specific physiological effects; TENS relies mainly on gate-control of pain
• B. H-Wave relies entirely on endorphin release; TENS relies on gate-control
• C. T-Wave uses ultrasound energy; H-Wave uses electrical energy
• D. H-Wave increases pain by stimulation; T-Wave decreases pain

Answer: (A)