C as in China rather that china if you are referring to China as in the country. Countries are proper nouns and should therefore start with a capital letter. If you are referring to porcelain there is no capital unless it starts a sentence.
On an unrelated question the capital city of China is Beijing.
Beijing
Chinas capital is Beijing. An ancient Chinese capitol was Xi'an
No it is not.
The capital letter of Australia is "C".
The Greek capital letter for Phi is Φ.
The Greek capital letter for Lamda is Λ.
The Greek capital letter for Xi is Ξ.
One china is made out of the mainland China, with Beiging as its capital, while the other is of Taiwan, an Island, that does not follow mainland Chinas view or rule.
Use communist Chinas official name in public
Disputes in the ROC.
Xinjiang
Confucianism.