What was one significant indication that the European feudal system was effective?

Similar systems developed in China and Japan.
European peasants voted to keep the system in place.
Invaders did not manage to attack Europe.
The system put an end to the Roman Empire.

Question

What was one significant indication that the European feudal system was effective?

Similar systems developed in China and Japan.
European peasants voted to keep the system in place.
Invaders did not manage to attack Europe.
The system put an end to the Roman Empire.

anonymous · Answer

Well, Rome fell due to their own governmental problems, so D is wrong.
Also, Europeans were never allowed to vote, regardless still.
And that leaves A and C.
There were still many attacks on Europe after the adoption of feudalism, as far as I know of, and China and Japan did indeed adopt feudalism.
So the answer is A.

anonymous · Answer

I might be wrong, but I'm pretty positive I'm correct.
I hope this helps.

anonymous · Answer

it really does thank you @Khirro