How did feudalism dependent on other classes ( pls pls pls give me the answer .

By the High Middle Ages (about 1000 CE), feudalism was completely developed and the Europeans benefitted from it. Feudalism established a strong social order that provided protection and safety. Under feudalism, Europeans were linked to each other with promises which helped both parties, up and down in the hierarchy. The feudal system was just like an ecosystem - without one level, the entire system would fall apart.

if i am correct the answer is going to be a) the federal program of reconstruction ended.

what are the reasons