Explanation:

- The Swadesh Darshan Scheme is an initiative by the Ministry of Tourism to develop theme-based tourist circuits in India to boost both domestic and international tourism.

- Option 1: Mahabharata Circuit

- The Mahabharata Circuit is not officially listed as one of the 13 thematic circuits under the Swadesh Darshan Scheme.

- It is focused on initiatives that connect places significant to the epic Mahabharata, but not part of the original list.

- Option 2: Ramayana Circuit

- Focuses on sites related to Lord Rama's journey as mentioned in the Ramayana.

- It is indeed one of the thematic circuits.

- Option 3: Desert Circuit

- This circuit aims to promote tourism in India's desert regions, like Rajasthan.

- It is part of the thematic circuits under the scheme.

- Option 4: Tribal Circuit

- This circuit highlights the culture and heritage of India's tribal communities.

- It is also part of the scheme's thematic circuits.

- Correct Answer: Option 1: Mahabharata Circuit