Which of the following actions is an example of historiography?

a.) a student sites credible sources to defend his argument that the roman empire was the wealthiest ancient civilization.

b.) an author discovers that an early greek historian exaggerated his claims to make them more entertaining.

c.) a historian relies on primary, rather than secondary, sources when writing a text book about ancient egypt.

d.) an archaeologist who discovers the ruins of an ancient chinese city sends them to a historian for analysis.