Concept:
China has multiple dialects, but the official standard language is Mandarin (Putonghua).
Step 1: Identify official language.
Mandarin Chinese (Putonghua) is the official language of China.
\[
\boxed{\text{Mandarin = Official language of China}}
\]
Step 2: Compare options.
Only option (B) is correct.
\[
\boxed{\textbf{Option (B)}}
\]