Which state celebrates the Bir Chilarai Divas?

Explanation: Assam celebrates the Bir Chilarai Divas every year, to commemorate the birth anniversary of the brave General of Assam, Chilarai. Chilarai was a great general of the Koch Royal Dynasty of Assam. He played a significant role in expanding the great empire of his elder brother Maharaja Nara Narayan. Hence, option ‘a’ is the correct answer.