Which of the following is a typical biofeedback device available for personal use?

Wearable devices that track heart rate and stress levels are indeed a typical biofeedback device available for personal use. These devices gather physiological data in real-time, allowing users to monitor their body’s responses to various stimuli or situations, such as stress. By providing feedback on heart rate variability or other stress indicators, these wearables enable individuals to gain insights into their physiological state, encouraging self-regulation techniques to manage stress or promote relaxation.

Other options do not function as biofeedback devices in the same way. Reliable dietary supplements, while potentially beneficial for health, do not provide direct feedback on physiological processes. Standard exercise equipment aids in physical activity but lacks the feedback component that biofeedback devices offer. Traditional therapy books can provide valuable information and strategies for mental health, but they do not measure or display physiological data to the user, which is a key feature of biofeedback technology.