Which of the following state was carved out of Assam in 1972?

Meghalaya

The correct answer is Option (2) → Meghalaya

Another major reorganisation of states took place in the north-east in 1972. Meghalaya was carved out of Assam in 1972. Manipur and Tripura too emerged as separate states in the same year. The states of Mizoram and Arunachal Pradesh came into being in 1987. Nagaland had become a state much earlier in 1963. 

Note 1: Manipur became independence along with India in 1947. In 1956, it became a Union Territory and got full statehood on 21 January 1972. hence, it was not carved out of Assam as asked in the question.(This fact not mentioned in NCERT).

Tripura (1972): Surrounded by Bangladesh on three sides, Tripura remained a Union Territory till 1972, when it became an independent state. (This fact not mentioned in NCERT).

Nagaland (1963): This state was formed on 1 December 1963. It is separated from Assam.