The correct answer is: "Allied forces came in and crushed the rebellion".
The Boxer Rebellion took place in China between 1899 and 1901, and it constituted an anti-imperalist, anti-christian and anti-colonial movement, that fought against the imposition of the influence and culture of Western countries, due to colonialism procedures.
As a response, Allied forces arrived to China and extinguished this rebellion. Those forces came from the US, the Astro-Hungarian Empire, Great Britain, France, Germany, Italy, Japan, and Russia.
