Final answer:
The best description of the effect of the Congress of Vienna on European geopolitics is that France was effectively contained by strong neighboring powers. The political landscape was reshaped to create a balance of power, with stronger entities surrounding France to prevent its dominance.
Step-by-step explanation:
The actions of the delegates at the Congress of Vienna, which aimed to restore a balance of power in Europe by redrawing the political map after Napoleon's defeat, had several significant geopolitical effects. The creation of the Kingdom of the Netherlands, the independence of Switzerland, and the formation of the German Confederation were part of these measures.
Of the given options, the sentence that best describes the effect of the delegates' actions is that France was effectively contained by strong neighboring powers. The assembly at the Congress of Vienna sought to prevent any single nation, particularly France, from becoming overly dominant again and thus destabilizing the continent.
They did this by fortifying the states surrounding France, creating buffer zones and balances of power that included various newly united or strengthened regional entities. Therefore, the geopolitical landscape of Europe was significantly influenced by diplomatic efforts seeking to contain French power and maintain stability through a balance of power.
While Prussia and Austria certainly gained in prominence, Prussia did not immediately become the most powerful country, and Russia was not weakened by the containment of France.