Which of the following statements is/are correct?

a. Gathering information and monitoring the possibilities of landslide is not only difficult, but also immensely cost-intensive. b. All the Himalayan states and the states from the Northeastern regions, except the plains of Assam, are included in the very high vulnerability zones. c. Mountainous areas in Andaman and Nicobar, high rainfall regions with steep slopes in the Western Ghats and Nilgiris are included in the high vulnerability zones.