Answer:
C. it united farmers for many different parts of the country into a single movement.
Step-by-step explanation:
Farmers' Alliance didn't contribute with money because they were lacking of it. Their reason to support Populists was the deflation, falling prices, high tariffs and high rail shipping rates. All this situation was hurting farmers' economy.
So, basically farmers support them because they were in debt and having a lot of issue with money.