Answer:
c. Norms.
Explanation:
When Elena noticed her friend getting uncomfortable when she kisses him on the cheeks as a form of greeting she was violating his norms.
Norms are something that is standard or typical.
In USA there they not used to kiss on the cheeks to greet their friends there would be some other norm of greeting someone.
I think it is the model ET-2. Not quite sure.
All counties. Much more info. Although most layers are just excel files with geographical reference data in them. That one file may be several MB as the state file may be 1mb or less