I'm guessing its the fall of China's last dynasty or the fall of Qin Shi. Hope I could help
The answer is true just because
The answer would be C., Suversive activity.
Subversive activity refers to all willful acts that have the intention of being detrimental to governmental interests that don't really fall into the specific categories of; treason, sedition, sabotage... etc
The equilibrium is the price that comes out from adding all the direct related costs in producing the good or service. To this total you have to add the indirect costs, for example, taxes, salaries, etc. Add up both results and you will have the price.
The equilibrium price is the price that covers all your expenses, both direct and indirect. With this price you do not lose nor earn any money.