Duncan Passage is a narrow strait located between South Andaman and Little Andaman islands in the Andaman and Nicobar Islands chain. It serves as an important shipping route connecting the Andaman Sea and the Bay of Bengal.
Option 1, "South and Little Andaman," correctly identifies the locations between which Duncan Passage is situated. South Andaman refers to the southernmost island in the Andaman group, while Little Andaman is a separate island located to the south of South Andaman. Therefore, option 1 accurately describes the geographical position of Duncan Passage.
Options 2 and 3 identify different islands in the Andaman archipelago, but they are not adjacent to Duncan Passage. Option 4, "Andaman and Nicobar," is incorrect as it does not specify the specific islands between which Duncan Passage is located.