Final answer:
The high-frequency current commonly used in the barbershop is the Faradic current (option B), which is an alternating current (AC) that produces muscle contractions when applied to the body. It is commonly used in electrotherapy and physical therapy treatments to stimulate and tone muscles.
Step-by-step explanation:
In the context of the question, the high-frequency current commonly used in the barbershop is the Faradic current (option B). Faradic current is an alternating current (AC) that produces muscle contractions when applied to the body, and it is commonly used in electrotherapy and physical therapy treatments. This type of high-frequency current is used to stimulate and tone muscles, which can be beneficial for various purposes in a barbershop setting, such as facial treatments or scalp massages.