Explanation:

Statement 1 is correct: In 2014, The government of Telangana declared Bonalu a state festival. The festival history reportedly started in 1813 in the region of Hyderabad & Secunderabad when a plague disease had broken out in the Twin Cities that had claimed thousands of lives. A military battalion from Hyderabad was then deployed to Ujjain and concerned about the plague menace in Hyderabad the military battalion offered prayers to Mother Goddess at Mahakali Temple in Ujjain, Madhya Pradesh, that if people get relieved from the epidemic they would be installing the idol of Mahakali back in Secunderabad. It is believed by devotees that Mahakali halted the spread of the disease while the Military Battalion came back here & installed an idol by offering Bonalu to Mother Mahakali. Statement 2 is correct: Bonalu is a Hindu Festival where Goddess Mahakali is worshiped. It is an annual festival celebrated in the twin cities Hyderabad and Secunderabad and other parts of Telangana state, India. Statement 3 is not correct: Bonalu, also known as Ashada Jatara is one of the biggest festivals of Telangana. It is observed once a year during July/August.