Which of the Following Is an Example of the Dual-Language

Which of the following is an example of the dual-language approach in a U.S. school?

A) Ron's first language is English, and he is taking a Spanish course in middle school.
B) Maria's first language is Spanish. She has a teacher who speaks Spanish during some of her classes and English in others during her initial years at school.
C) Lynn's first language is English, and she takes a Spanish class to learn Spanish for her own interest.
D) Anibal's first language is Spanish. He is taking a Spanish literature class taught in Spanish in addition to his regular classes, which are taught in English.