The proposed sea-route "Sethu Samudram" is a canal that aims to connect the Gulf of Mannar and the Palk Bay, which are located between the southeastern coast of India and the northern coast of Sri Lanka. The canal would provide a shorter and more efficient route for ships to navigate between the east and west coasts of India, avoiding the need to sail around Sri Lanka.

Option 1, Gulf of Mannar, is the correct answer because the Sethu Samudram canal would be constructed in this area.

Option 2, Malacca Strait, is incorrect as it is a different sea-lane located between the Malay Peninsula and the Indonesian island of Sumatra.

Option 3, Gulf of Kutch, is also incorrect as it is located on the western coast of India, far from the proposed Sethu Samudram canal.

Option 4, Andaman and Nicobar Islands, is also incorrect as this group of islands is located in the Bay of Bengal, which is separate from the proposed canal route.