Final answer:
The narrowest Turkish strait between the Sea of Marmara and the Aegean Sea is the Bosporus, which is only a mile wide at its narrowest point and is correctly identified as option (a) Bosporus.
Step-by-step explanation:
At its narrowest point, the Turkish strait between the Sea of Marmara and the Aegean Sea is the Dardanelles, also historically known as the Hellespont. This narrow strait separates the European and Asian parts of Turkey. The question refers to a strait that is only a mile wide at its narrowest point, making the correct answer to the question (a) Bosporus.
Incorrect options include the Suez Canal, which is an artificial sea-level waterway; the Gibraltar Strait, which separates Europe from Africa; and the English Channel which separates Great Britain from continental Europe. The Bosporus strait is a natural, narrow, and strategic waterway that connects the Black Sea to the Sea of Marmara, and then via the Dardanelles to the Aegean and Mediterranean Seas. Control of the Bosporus has been a significant strategic goal throughout history, including during the time of the Ottoman Empire, which used its control of Gallipoli on the Dardanelles to manage naval traffic and assert power in the region.