I. It became an integral part of India in 1975.
II. It is considered as a botanist's paradise.
III. Its population is mainly made up of the Lepchas.
Correct Answer: (d) I, II and III
Solution:By 36th Amendment of the Constitution, 1975, Sikkim became an integral part of India. This region is blessed with biodiversity and considered as the Paradise of Botanists because it comes under the Himalayan hotspot. Natives of this region are Lepchas, Bhutias, and the Nepalis.