Explanation

Option D is correct: Valley of Flowers National Park, situated in the Chamoli district of Uttarakhand in the Western Himalayas, is located at an altitude between 3,200 and 3,700 metres up to 6,700 metres above sea level, lying completely within the temperate, sub-alpine, and alpine bioclimatic zones:

– Manas National Park (Assam): Lies in the tropical and sub-tropical foothill terai plains.
– Namdapha National Park (Arunachal Pradesh): Features wide altitudinal variation from 200m (tropical evergreen) to over 4,500m (alpine), meaning it does not lie *completely* in the alpine zone.
– Neora Valley National Park (West Bengal): Spans subtropical to temperate broadleaf hill forests.

Therefore, the national park is Valley of Flowers National Park — Option D.