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 until Maria can learn more English.
C) Lynn's first language is English, and one of her teachers sometimes speaks Spanish so the children can learn a little of the language.
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.