How is culture transmitted from one generation to another?

Parents and family have initial responsibility for cultural transmission, but education theorists have applied the concept to the classroom where a teacher conveys a common body of knowledge and cultural norms to students, either formally or informally. Some critics such as E. D. Hirsh argue that a core knowledge base is being superceded by multiculturalism. Some educational theorists say that cultural transmission goes beyond conveying facts and the focus of education is to prepare its students to adapt to the constantly changing culture and its demands.

Ibelieve he answer is a, but correct me if i'm wrong.