Arakan Mountains, also known as the Rakhine Mountains, are a mountain range in western Myanmar. It is the most prominent of a series of parallel ridges that arc through the Indian States. Which of the following is not one of them?

The Arakan Mountains, also known as the Rakhine Mountains, are a mountain range in western Myanmar, between the coast of Rakhine State and the Central Myanmar Basin, in which flows the Irrawaddy River. It is the most prominent of a series of parallel ridges that arc through Assam, Nagaland, Mizoram and Myanmar. Hence, 2 is the correct answer.