Read the given paragraph and answer the following question:

One such individual was the Italian revolutionary Giuseppe Mazzini. Born in Genoa in 1807, he became a member of the secret society of the Carbonari. As a young man of 24, he was sent into exile in 1831 for attempting a revolution in Liguria. He subsequently founded two more underground societies, first, Young Italy in Marseilles and then, Young Europe in Berne, whose members were like-minded young men from Poland, France, Italy, and the German states. Mazzini believed that God had intended nations to be the natural units of mankind. So Italy could not continue to be a patchwork of small states and kingdoms. It had to be forged into a single unified republic within a wider alliance of nations. This unification alone could be the basis of Italian liberty. Following his model, secret societies were set up in Germany, France, Switzerland, and Poland. Mazzini's relentless opposition to monarchy and his vision of democratic republics frightened the conservatives. Metternich described him as ' the most dangerous enemy of our social order '

Which of the following sentence is correct according to the paragraph?