Explanation:
Prime Minister Narendra Modi remembered Sardar Vallabhbhai Patel on his 71st death anniversary on December 15, 2021. Sardar Vallabhbhai Patel had passed away on December 15, 1950 in Bombay after suffering a massive heart attack. He is called the 'unifier of India' as he had played a key role in the integration of all princely states into the Indian Union.