What did the tang dynasty do to try and make its government more efficient and effective a) required government officials to be confucian scholars b)built the grand canal and repaired the great wall c)brought back the civil service examination system d)created a legislative body made up of common citizens

This is C. brought back the civil service examination system.

C. Brought back the civil service examination system is the correct answer.

Explanation:

In the traditional Chinese government the government officials were selected by competitive civil services examination and gave stability to the Chinese empire for more than 2000 years. The examination was also important for social mobility.  It was a model for the civil services that came up in Western and Asian countries.  

The first bureaucratic empire was established by the Qin dynasty and recruited the official on the recommendation by local officials. It was later adopted by Han dynasty. Sui dynasty also applied it in a much systematic way to recruit the officials.  The tang dynasty created local schools where the scholars could study for civil services exams.

35 is your answer because i looked it up