What were the five classes (in order) of society during the “Neo-Confucian” era?

In Neo-Confucian era the five social classes or orders in the family are ruled to ruled, father to son, husband to wife, elder brother to younger brother and friend to friend.  

Explanation:

In Neo-Confucian era the social hierarchy or classes were made in the family on basis of relationship. That family bonding was described as ruled to ruled, father-son, husband to wife, elder brother to younger brother and friend to friend. Each of the class has their own sets of responsibility.

In a family each class has its own responsibilities and accountability to others like elder brother, father and husband has duty and responsibility to his subordinate like younger brother, son and wife respectively.

the answers is b.   environments.

to keep us neatruel and not get involved in any wars

he assumed control of treaty negotiations with a hostile power