What was the purpose of the pershing expedition?

Pershing Expedition(1916-1917) was a US military mission in Mexico. The reason for dispatching the US army was that during the Mexican revolution General Pancho Villa could not control the Mexican revolution it tried to draw the US into the conflict by raiding the bordering area of New Mexico and killing the residents. In order to capture Villa, the US government sent Brigadier John J. Pershing with a force of 6600 men. The expedition was unsuccessful because Pershing could not find VIlla. The expedition came to be known as Pershing Expedition.

i believe the answer is a

a.   it resulted in widespread unemployment.