I believe the answer is: Consciousness
Consciousness allow you to analyze the internal capabilities that you have and the factors that influence the situation around you.
By knowing this information, you have the capability to identify the next decision/course of action that would benefit you the most.
The answer is A: The development of the first mathematical system of perspective
Depression. they suffer from depression
The definition of political anthropology is the study of political systems as the basic structure of a society
Source: http://www.yourdictionary.com/political-anthropology