Answer: Option C is the most correct option. Rules are learned by modeling our behavior after our parents and others.
Explanation: Culture can be defined simply as the people's way of life.
We have two ways of learning, which are formal education and the informal education. Formal education are those things we learn from school or from a learning gathering. While the informal education are the one we learn at home from our parents, siblings, uncle's, neighbors, and others.
Since the questions was about the informal level of culture, it should be about the culture we learn from home.
The rules of a culture is the correct way of how to practice the culture, the informal way to acquire those rules is when we learn from our parents at home.