The correct answer is: October 1.
Haryana Day is a public holiday in the Indian state of Haryana. It is celebrated on October 1 to commemorate the formation of the state on October 1, 1966. The day is marked with a variety of events, including cultural programs, parades, and speeches.
Option A: September 1 is not Haryana Day. Haryana Day is celebrated on October 1, not September 1.
Option B: October 1 is Haryana Day. Haryana Day is celebrated on October 1 to commemorate the formation of the state on October 1, 1966.
Option C: November 1 is not Haryana Day. Haryana Day is celebrated on October 1, not November 1.
Option D: December 1 is not Haryana Day. Haryana Day is celebrated on October 1, not December 1.