The correct options are
A Sikhs, Hindus and Muslims in Punjab and Bengal legislative assemblies would vote for partition.
B A boundary commission to be set up in case of partition.
C North West Frontier would vote for partition.
According to the Mountbatten plan, people in Punjab and Bengal legislative assemblies would meet and vote for partition. Sindh was to take its own decision. The North West Frontier Province and Sylhet district of Assam were to have a referendum. The plan also stated that India would be independent by 15th August, 1947. Independence of Bengal was ruled out. A boundary commission was to be set up under the plan. The princely states could join any one of the unions and they were free to remain independent.