Answer:
At the Congress of Vienna, the country of Belgium:
c. became part of the Netherlands.
Step-by-step explanation:
The Congress of Vienna was a meeting of European ambassadors that took place in 1815 after the Napoleonic Wars, with the intent of reorganizing Europe and maintaining the peace. During this Congress, it was decided that Belgium and Holland (the Netherlands) would be united into a single State, ruled by King William I. However, that did not happen without objection. King William was a protestant, and the Catholics were not happy about his interference in their matters.