Which one of the following National Parks has a climate that varies from tropical to subtropical, temperate and arctic?

The answer is D, Namdapha National Park, in the eastern Himalaya of Arunachal Pradesh. Its altitude runs from about 200 m in the Noa-Dehing lowlands to about 4,571 m near Dapha Bum, so its vegetation and climate pass from tropical evergreen forest through subtropical and temperate zones to alpine and near-arctic conditions. That full span is what the question is testing.

Why the others are wrong:

• A) Khangchendzonga: Sikkim's high-altitude park around Kanchenjunga. It is mainly alpine and temperate, with no tropical lowland belt. It became a mixed World Heritage Site in 2016, after the exam year.
• B) Nanda Devi: Uttarakhand's high-altitude park. It is alpine and sub-alpine, so it does not cover the tropical end of the range.
• C) Neora Valley: A small park in the Darjeeling-Kalimpong hills of West Bengal, known for its subtropical and temperate forests and the red panda. It does not reach arctic conditions.

Namdapha also has a Tiger Reserve and Biosphere Reserve status and is one of the few Indian parks with four big cats. For Mains (GS-III, environment and biodiversity), it illustrates how altitudinal gradients drive species distribution in the Eastern Himalaya and Indo-Burma hotspot.

Trap: Candidates pick the famous high-altitude parks like Nanda Devi or Khangchendzonga because they sound extreme. The question asks for the whole range from tropical lowlands upward, and only Namdapha covers it.