The change of yin and yang in four seasons has great influence on the yin and yang of human body. In spring, the yang in nature begins to rise, and the yang in the human body also begins to grow from the inside out, which is the most taboo. Therefore, everything in the human body that contributes to the growth of yang is smooth, and inhibition is reverse. In summer, the yang in nature is the most abundant, and the yang in the human body tends to the body surface, so it is easy to disperse outside, so it is good to protect the yang, but not good to disperse the yang. In autumn, the yang of nature begins to decline, and the yang of human body tends to be in the body; In winter, the natural yang drops greatly, and the human body is full of yang. Therefore, in autumn and winter, the yin essence of the human body is easy to consume, and maintenance is the most important. Therefore, Su Wen's theory of four qi regulating the spirit puts forward the principle of "nourishing yang in spring and summer and nourishing yin in autumn and winter". So, the question should be B.