Analysis of test questions: the essence of education is the basic stipulation of things, and it is the essential feature that distinguishes one thing from other things. The essence of education is the qualitative stipulation of education as a special social practice, and the question to be answered is "What is education". People's answer to the question "What is education?" can directly reflect his educational vision and generally determine his understanding of the extension, connotation, phenomenon and essence of education, which is a fundamental educational theory and viewpoint. Choose C.