The Sagarmanthan National Park has been established to preserve the eco-system…

Concept: Many high-altitude national parks are named after the peak or massif whose ecosystem they were created to protect, and Himalayan summits usually carry a local-language name alongside the English name used internationally. Recognising the local name inside a park's title therefore identifies the peak it guards.

Application: The park meant here is officially Sagarmatha National Park; the spelling "Sagarmanthan" printed in the paper is a typographical slip for Sagarmatha. "Sagarmatha" is the Nepali name of the world's highest summit, called Mount Everest in English and Chomolungma in Tibetan. The park was created in 1976 in the Solukhumbu district of Nepal's Khumbu region, covers the upper catchment of the Dudh Koshi river, and was inscribed on the UNESCO World Heritage List in 1979 for that high-altitude ecosystem of snow leopard, Himalayan tahr, musk deer and Impeyan pheasant.

Cross-check: Each of the other named entities belongs to a different protected area, or is not a Himalayan summit at all:

Result: The park whose Nepali name is Sagarmatha preserves the eco-system of Mount Everest.