Consider the following statements about Indo-Tibetan Border Police (ITBP) : 1. ITBP was raised in 1962. 2. ITBP is basically a mountain trained force. 3. ITBP replaced Assam Rifles in Sikkim and Arunachal Pradesh in 2004–2005 for border guarding duty. 4. ITBP presently has 52 service battalions. Which of the statements given above are correct?