Sardar Vallabhbhai Patel was equated with Bismarck. This means that he shared similarities with Otto von Bismarck, a prominent figure in European history. Bismarck was known for his role in the unification of Germany in the late 19th century. Similarly, Patel played a crucial role in the unification of modern-day India after its independence from British rule. Both leaders used their political skills and strategic thinking to unify their respective nations and overcome challenges. Although Mazzini, Cavour, and Garibaldi were also significant figures in the unification of Italy, they are not directly relevant to the comparison made between Patel and Bismarck. Therefore, Option 4 is the correct answer.