The correct option is D Belgium became part of Holland
In 1815, the Treaty of Vienna was signed among the major powers of Europe. Its main decisions included -
i) Restoration of Bourbon Dynasty in France,
ii) Transfer of most of Poland to Russia,
iii) Loose confederation of states in Germany,
iv) Belgium became part of Holland.
Through the Treaty of Vienna, conservative regimes were restored across Europe. These were autocratic and imposed severe censorship.