In the process of person perception, we initially form a very rapid first impression based largely on looking at other people's faces. According to the textbook, if you glanced at a stranger's face for only one tenth of a second:

Apolitical machine ~ apex 

The correct answer is a. when they started making tools that will them in cultivating lands, they could raise crops and that made them attached to one place for a longer period of time. after that, they started domesticating animals and building their own permanent settlements that resemble the ones we have today.