When did Chinese characters develop into conscious calligraphy art?

The development of China's calligraphy art has experienced two stages: spontaneous and conscious. The development of Chinese characters into conscious calligraphy art is in:

A. Neolithic Age B. Shang and Zhou Dynasties

C. Qin and Han dynasties D. Wei, Jin, Southern and Northern Dynasties

D. Wei, Jin, Southern and Northern Dynasties

During the Wei, Jin, Southern and Northern Dynasties, the aesthetic function of calligraphy exceeded the practical function, and Chinese characters developed into a conscious art of calligraphy, becoming an ideal form for literati to express artistic conception, charm and character.