Acollection of people who exist in same place at the same time, but who don't interact or share a sense of identify are known as:

Crowds

Explanation:

Crowds

crowds referred to that collective group of people who are available at one place but don't interact to each other. It is a large group of people gathered at some place.

The our category of crowds are

1) casual crowds

2) conventional crowds

3) expressive crowds

4) acting crowds

the united states has a federal government. the president is the head of the federal government of the united states. however, each state forms its government for administration purposes. the powers of the state governments are exercised within restricted state boundaries. and citizens participate in this government by voting.

the correct answer is c.