Analysis of test questions: This question mainly examines students' ability to remember the contents of the textbook. "Xian" and his son were calligraphers in the Eastern Jin Dynasty. Wang Xizhi learned from others and prepared various styles. Because he is good at cursive script and running script, he is respected as a "book saint" by later generations. Calligraphers Ou Yangxun, Yan Zhenqing and Liu Gongquan in the Tang Dynasty created the European style, Yan style and Liu Ti of regular script, which were used for reference and copied by later generations. Huai Su and Zhang Xu's Weeds also have artistic charm. Su Shi, Huang Tingjian, Mi Fei and Cai Xiang are known as the four great calligraphers in the Northern Song Dynasty, and they are all famous for their running scripts. In the Ming Dynasty, Wen Zhiming and Dong Qichang enjoyed the highest reputation. "Zhang Xu Zhangdian" is not a brother, and the calligraphy in the Tang Dynasty cannot represent the highest level in China. So the answer is a.