In India, the postal department was set up in?

Which of the following statements is/ are correct?

1. Konyak languages are spoken in Nagaland
2. The largest river island in the world is in Assam
3. Arunachal Pradesh has the least density of population in India
4. The largest desert in the world is situated in India

Choose the correct option from the codes given below:

[A] 1 & 2
[B] 1, 2 & 3
[C] 1, 2 & 4
[D] 1, 2, 3 & 4

Mountain ranges in the eastern part of India forming its boundary with Myanmar are collectively called as _______

Which one of the following is the coldest place in India? 

(a) Srinagar (b) Dras

(C) Gulmarg (d) Pahalgam.