Which Indian leader is popularly known as the Bismarck of India for his role in national integration?

Introduction / Context:
Many political leaders are given historical epithets that highlight their achievements. The title Bismarck of India refers to the nineteenth century German statesman Otto von Bismarck, who unified Germany. In the Indian context, the same label is used for the leader who integrated numerous princely states into the Indian Union after independence.

Given Data / Assumptions:

• The question asks for the Indian equivalent of Bismarck.
• The field is national integration and state unification.
• The options list prominent Indian freedom fighters and leaders.

Concept / Approach:
The correct association is with Sardar Vallabhbhai Patel, who served as Deputy Prime Minister and Home Minister in the first government of independent India. He led the process of persuading and sometimes pressuring princely states to accede to the Indian Union. His role in welding a fragmented map into a unified country earned him the comparison with Bismarck.

Step-by-Step Solution:
Step 1: Recall the major responsibilities of key leaders after independence.Step 2: Identify that Sardar Vallabhbhai Patel was in charge of the Home portfolio and states affairs.Step 3: Remember that he integrated more than five hundred princely states, using diplomacy and firmness.Step 4: Match this achievement with the epithet Bismarck of India and select his name from the list.

Verification / Alternative check:
A quick check is to connect each option with their main historical identity. Jawaharlal Nehru is best known as the first Prime Minister and architect of India's foreign policy and planning. C. Rajagopalachari was the last Governor General of India. K. Kamaraj is remembered for political leadership in Tamil Nadu and for the Kamaraj Plan. Subhas Chandra Bose led the Indian National Army. None fits the specific role of post independence integration the way Patel does.

Why Other Options Are Wrong:
Although Nehru played an important role in guiding the new nation, he is not primarily credited with the integration of princely states. Rajagopalachari and Kamaraj were influential leaders but did not lead the complex negotiations over accession. Subhas Chandra Bose focused on external military efforts against colonial rule and was not alive to shape the post independence unification process. Hence these names are incorrect in the context of this epithet.

Common Pitfalls:
Learners sometimes pick the most famous leader, often Nehru, when they see a title related to nation building. Another mistake is to confuse the roles of different freedom fighters because they all appear in the same chapters. To avoid this, it is helpful to remember a few signature contributions, such as Patel for integration of states, Nehru for planning and foreign policy, and Ambedkar for drafting the Constitution.

Final Answer:
The correct answer is Sardar Vallabhbhai Patel.