According to the Text, Which of the Following Is a Principle

According to the text, which of the following is a principle of second-language acquisition in the classroom?

A) The social context for learning a second language must be a setting in which students feel accepted and comfortable.
B) Students in small groups and pairs have natural opportunities for meaning-making and authentic communication.
C) Students need time to listen and process without the pressure of oral and written production. They are often rehearsing and creating systems while silent.
D) All of the above