CORRECT ANSWER = ESSENSE AND BLOOD. (4 points)

While some of the other choices may be indirectly linked with the practice of Qigong, the "Sun Wen: On the Theory of Yin-Yang" says, "Essence turns into Qi" and that the "Transformation of Qi promotes The Increase of Essence". Qi is often referred to as the "commander" of the blood and blood is the "mother of Qi". Qi and blood are interdependent. They rely on each other. "Qi gives warmth while blood gives moisture", they act on each other in continuous circulation through the body in the process of metabolism, growth, development, physiological activities, and life activities of the body.