Why were they called the “bonus army”?

Explanation:

Organizers called the demonstrators the "Bonus Expeditionary Force", to echo the name of World War I's American Expeditionary Forces, while the media referred to them as the "Bonus Army" or "Bonus Marchers". ... The principal demand of the Bonus Army was the immediate cash payment of their certificates.

china unilaterally claims the entire south china sea as sovereign territory, then builds artificial islands to bolster its claim. it suddenly activates an air defense identification zone over the east china sea, and threatens to down any aircraft that does not report its position. it builds roads into indian territory, then redraws the maps to show that it is actually chinese territory. the people's republic under president xi jinping is quickly becoming the bully of asia.

c.) the country needed a stronger central government.