Final answer:
The Isthmus of Panama is the physical feature located at the Isthmus of Panama, known for the Panama Canal that connects the Atlantic and Pacific Oceans. The correct option is (d).
Step-by-step explanation:
The physical feature located at the Isthmus of Panama is indeed the Isthmus of Panama itself.
This narrow strip of land serves as a land bridge connecting the North and South American continents, with the Pacific Ocean on its west and the Caribbean Sea on its east.
The significance of the Isthmus of Panama is highlighted by the presence of the Panama Canal, a man-made waterway that crosses the isthmus, allowing for ship passage between the Atlantic and Pacific Oceans, which was constructed by the United States between 1904 and 1914.