Question

for europe, the most positive result of the congress of vienna was that
the balance of power was restored.
napoleon would never again take power.
european countries formed an economic alliance.
european countries would now work together.

Explanation:

The Congress of Vienna's main goal was to restore the balance of power in Europe after the Napoleonic Wars. Napoleon's final defeat (like at Waterloo) already ensured he wouldn't take power again, so that's not the most positive result of the Congress. European countries didn't form a broad economic alliance at the Congress, and while cooperation was a by - product, the core achievement was the balance of power restoration to prevent future domination by one state.

Answer:

A. the balance of power was restored.