During the Qin Dynasty, the great wall was built to fortify the northern border to * 4 points
1. protect the silk route
2. provide irrigation
3. for flood control
4. stop invading barbarian attacks

1) the taiping rebellion was prompted from 1850-1864 and waged against the ruling of machu qing dynasty. the rebellion was caused by hong xiuquan and class differences, later leading to a radical change in social and economic structure.

3) karl marx, a believer of the principle of socialism, believed that the working class would have to free themselves from the exploitation of industrialists by establishing a radical socialist classless society where all industries and   property are owned by the state.

5) as indians revolt gained power, people found additional reasons to protest against the british rule. princely families joined the uprising due to changes to the inheritance law which made adopted children ineligible to assume the throne. this was an attempt by the british to control royal succession in the princely states that were nominally independent from the british.

i think the answer is the one about environmental and social health.

hope this