B；
The two terms cannot be confused. An official language has been officially recognized by some government authority, while a national language can refer either to a language serving an entire nation or to a language functioning as a national symbol.
这两个术语不能混淆。一种官方语言已得到一些政府当局的正式承认，而一种民族语言既可以指为整个民族服务的语言，也可指作为国家象征的语言。
