Explanation:

• Rashtriya Ekta Diwas 2019 (National Unity Day) was celebrated all across the country on 31st October to commemorate the 144th birth anniversary of Sardar Vallabhbhai Patel. • Sardar Patel played an instrumental role in India’s struggle for independence, and later during the integration of the country. • At the time of independence, Sardar Vallabhbhai Patel played a key role in convincing several princely states to align with the Indian Union. The day of his birth, therefore, celebrates his efforts and contributions.