Answer:
This is called cluster sampling procedure.
Explanation:
In this type of procedure, a group of elements is considered instead of individual units. This proceddure is usually based on geography, and it's useful due to its efficiency regarding cost and time.
There are a few disadvantages, though: it might not be diverse enough to be significant, and it's possible that some elements of other groups (in this case, other districts) share some features.
It encouraged a form of government where the rights and liberties of people were protected
