What was done to protect the Chinese empire against Invaders? O they attacked the enemies first
O built the Great Wall
Omore soldiers were drafted
O installed fortifications on the rivers

They built the Great Wall

Explanation:

The Ming dynasty built a giant wall stretching 5,000 miles to keep invaders out of China, but how effective was it against the enemy? The Great Wall is nearly 30 feet high along some stretches, and often built through rugged and mountainous terrain, such as the Huanghuacheng region near Beijing.

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.

the answer to this question is the third option. hope this