What does a cultural historian study?
a. the development of specific groups of people, or of particular ways of organizing human life
b. the development of art, manners, ceremonies, dress, and other aspects in a culture
c. the evolution of forms of government, political institutions, governmental relations, and political processes
d. the changes in religious practice and beliefs through time

b. the development of art, manners, ceremonies, dress, and other aspects in a culture  

Explanation:

A cultural historian often combines the approaches of anthropology and history to look at the traditions of popular culture and cultural interpretations of historical and human experience. This historian is concerned with the research and representation of a given culture in a given period and place. It is not directly dedicated to the political history or official history of countries or regions. The cultural historian devotes his research to studying the development of art, manners, ceremonies, clothing, and other aspects of a region's culture.