Explanation:

- Dashain is a significant festival celebrated by Hindus.

- It is of great importance in Nepal, spanning over 15 days.

- The festival marks the triumph of good over evil.

Option 1: Myanmar

- Myanmar primarily celebrates Buddhist festivals like Thingyan and Thadingyut.

Option 2: Bhutan

- Bhutan, predominantly a Buddhist nation, celebrates festivals such as Tshechu.

Option 3: Sri Lanka

- Sri Lanka's major festivals include Sinhala and Tamil New Year, Vesak, and Poson, largely influenced by Buddhism.

Option 4: Nepal

- Dashain is the longest and the most important festival of Nepal, deeply rooted in Hindu traditions.