The correct answer is - B. Chinese.
The Chinese language has seven dialects, and one of them is the Mandarin dialect. This is the dominant dialect in the country, spoken by the majority of the people, and it is also the dialect that is a must to learn in the educational system in this vast East Asian country.
Even though in China there are lots of other languages present and spoken, like the Mongol, Uighur, Tibetan, all of those languages are put behind the Mandarin dialect of the Chinese language, and everyone in the country has to learn it.