Which one of the following is correct about Assam in British India?

The correct answer is Option 3. In 1824 Assam was occupied by British forces following the First Anglo-Burmese War and on 24 February 1826, it was ceded to Britain by Burma under the Yandaboo Treaty of 1826 . Between 1826 and 1832 Assam was made part of Bengal under the Bengal Presidency . From 1832 to October 1838 the Assam princely state was restored in Upper Assam while the British ruled in Lower Assam . Purandar Singha was allowed to rule as king of Upper Assam in 1833 , but after that brief period, Assam was annexed to Bengal by the British . Purandar Singha who became the king of Ahom Kingdom twice (1818–19, 1833–1838) was the last king of Ahom kingdom in Assam . Ahom kingdom was a late medieval kingdom in the Brahmaputra Valley in Assam . It is well known for maintaining its sovereignty for nearly 600 years and successfully resisted the Mughal expansion in Northeast India . On 6 February 1874 Assam, including Sylhet , was severed from Bengal to form the Assam Chief-Commissionership , also known as the 'North-East Frontier' . Hence Option 3 is correct. Shillong was chosen as the capital of the Non-Regulation Province of Assam in September 1874. From 16 October 1905 Assam became part of the Province of East Bengal and Assam. The province was annulled in 1911 following a sustained mass protest campaign and on 1 April 1912 the two parts of Bengal were reunited and a new partition based on language followed, Oriya and Assamese areas were separated to form new administrative units: Bihar and Orissa Province were created to the west and Assam Province to the east.