Which of the Following Is Now Known About Biofeedback as an Effective

Which of the following is now known about biofeedback as an effective relaxation technique?

A) Biofeedback is considered more effective than all other forms of relaxation techniques.
B) People can actually be taught to control their physiological functions.
C) Researchers are still uncertain why biofeedback works.
D) Biofeedback is considered more effective than all other forms of relaxation techniques, and people can actually be taught to control their physiological functions .
E) People can actually be taught to control their physiological functions, and researchers are still uncertain why biofeedback works.
F) All of these are correct.