The correct answer is 2 only: opening a new canal across the Kra Isthmus between the Gulf of Siam and the Andaman Sea can greatly reduce navigation time and distance between India and East Asia.
Explanation:
The Malacca Strait is a narrow waterway between Malaysia and Indonesia, connecting the Indian Ocean and the South China Sea. It is a major shipping route, but deepening it further may not be practical or feasible due to environmental concerns and the high cost involved.
On the other hand, the Kra Isthmus is a narrow land bridge in southern Thailand, separating the Gulf of Thailand and the Andaman Sea. Building a canal across the Kra Isthmus would provide a shorter and more direct shipping route between the Indian Ocean and the Pacific Ocean, bypassing the congested and sometimes pirate-infested Malacca Strait. This could greatly reduce navigation time and distance between India and East Asia, and boost trade and economic ties between the two regions.
Therefore, the correct answer is 2 only: opening a new canal across the Kra Isthmus between the Gulf of Siam and the Andaman Sea can greatly reduce navigation time and distance between India and East Asia.