The study of population is called.

Explanation:

Demography is the study of the population.
The population includes how many people there are, how they live, and how they change over time and space.
 Cartography is the science of making maps.
 Anthropology is the study of human cultures and societies.
 A biography is a written account of a person's life.

Final answer :

Hence, the correct option is C. Demography