4.
The answer is: C
Explanation
National Unity Day is an important day in India's calendar and is celebrated on October 31st every year. This day was introduced by the Government of India in 2014 to commemorate the birth anniversary of Sardar Vallabhbhai Patel, who played a pivotal role in the political integration of India.
Sardar Patel, who is often referred to as the "Iron Man of India," was instrumental in uniting the diverse and fragmented princely states into a single nation after India gained independence from British rule. As the first Deputy Prime Minister and Home Minister of India, he worked tirelessly to bring about the integration of the various states into the newly formed country.
National Unity Day is celebrated to honor Sardar Patel's vision of a united India and to promote the values of unity, peace, and harmony among the people of the country. The day is marked by various events, including parades, speeches, and cultural programs, that highlight the importance of national unity and the contributions of Sardar Patel.
The celebration of National Unity Day serves as a reminder of the sacrifices made by the country's freedom fighters and the importance of maintaining the unity and integrity of India. It is an occasion to renew our commitment to these ideals and work towards a stronger, more prosperous, and united India.