The correct option is A To remember the formation of the state of Karnataka, by merger of all Kannada-speaking regions of South India.
On 1 November, 1956, the Vishal Mysore State was formed by merging all the Kannada-speaking regions of South India. Subsequently, in accordance with the wishes of the people of the state, the state was renamed as Karnataka, in 1973. Since the Vishal Mysore State was formed on 1 November, this day is celebrated every year as Kannada Rajyotsava Divas, to remember the formation of the state.