What factors are necessary to cause a transition from one era to another

There are many factors that are involved when an era transitions to the next. It usually involves a large change in political, social, and economic factors. Examples are colonization, economic progress or downfall, or changes in the government. Each era has a corresponding theme that is heavily influenced by important events that have happened within it. Examples are the age of enlightenment, industrial revolution and the renaissance. 

the answer is false.

a countries leader should be motivated by the common good of the country.