Answer: Systematic study
Explanation:
Systematic study is the knowledge and information that is extracted from step by step technique in orderly manner.This field consist of facts and scientific content for studying any behavioral pattern. Systematic study is based on methods, research, observation etc.
According to the question, systematic study should also be considered as an addition to the instinctive ideas about human.It will provide knowledge and accuracy about the idea through methodical knowledge.
Since the question states that you need only one explained, the religion is the simplest because everything then was about Buddhism. It reached all levels of society and was widely practiced by many people, even described or seen thoroughly in works of literature or art.
3, 4, & 5 should all be correct
There was a major fire when "king" Nero ruled in this point in time. People blamed the fire of the Christians and then a whole bunch of tension broke out!