Option 1 states that India took a pledge of complete Independence on November 26, 1949. However, this is incorrect. India had already achieved independence on August 15, 1947.

Option 2 correctly states that the Constitution was adopted on November 26, 1949. This is a significant day in our constitutional history because it marks the formal adoption and enactment of the Constitution of India. The Constitution of India is the supreme law of the country and lays down the framework for governance, fundamental rights, and duties of citizens, and the structure and powers of various institutions.

Option 3 states that India became a Republic on November 26, 1949. This is also correct. On this day, India transitioned from being a constitutional monarchy to a sovereign democratic republic, with the President as the head of state.

Option 4 states that the first amendment of the Constitution was passed on November 26, 1949. This is incorrect. The first amendment to the Constitution was enacted on June 18, 1951.

Therefore, the correct answer is option 2.