(1) All instruction shall be in the English language, except:
(a) Those programs established under subch. VII of ch. 115 where instruction shall be in the English language and in the non-English language of the bilingual-bicultural education program.
(b) The school board may cause any foreign language to be taught to pupils who desire it.
(c) The school board may cause any course to be taught in a foreign language if the purpose is to facilitate the instruction of English speaking pupils in that language.
(2) A school board may grant foreign language credit to a pupil who has satisfactorily completed a high school course in American sign language.