Explanation:

- Option 1: Odisha

- Odisha has a substantial coastline along the eastern coast of India.

- It borders the Bay of Bengal.

- Option 2: Kerala

- Located on India’s southwestern coast, it borders the Arabian Sea.

- Known for beautiful backwaters.

- Option 3: Maharashtra

- Lies to the west and shares its coast with the Arabian Sea.

- It's an economic hub with major ports like Mumbai.

- Option 4: Gujarat

- Has the longest mainland coastline in India.

- Borders the Arabian Sea and Gulf of Khambhat.

- Correct Answer: Option 4 - Gujarat