Answer:
B.presence of rivers
Explanation:
Because presence of river led to development of agriculture .
Because those that knew the trade and worked hard for the job often did not get the job unless they knew someone. And sometimes people in the spoil system did not know how do their job. It wasn't merit based. Like is someone worked their whole life to be a doctor and a high school graduate becomes a doctor because they knew a friend who could hire them.
the telephone, it changed the way people communicate in a quicker and easier way
