Why did Chinese people build great wall during ancient time? Select one:
a. to keep out invaders from central Asia
b. To protect running water
c. to protect themselves from wind damage
d. In order to show their civilization

The answer is the spotlight effect.

Explanation:

In this phenomenon, people think they are more noticeable than they really are. This behaviour can be explained by the inaccuracy to evaluate other people's perceptions (i.e. we mostly think about ourselves, and we tend to forget others do the same).

This conduct is more promimennt when doing something highly uncommon, at least on an individual level.