A) Experts, graduate students and scholars who study the history of China certainly know the foreign countries with the deepest history in China, but experts also have their own parts in the field of history. For example, Ming Dynasty history experts may not know much about Han Dynasty history.
B) Foreigners who live in China or are interested in China have read some materials and have a certain understanding of the history of China, but not as much as experts.
C) The average American with a good comprehensive education should know some important people and things in the history of China, because they studied in school, but they don't know much about China.
I know nothing but the Great Wall.