Answer:
B. the Ishtmus of Panama
Step-by-step explanation:
North America (Central America too as a region of it) and South America are two continents that are physically connected through a land mass, more like a thin land bridge, known as the Ishtmus of Panama. The term ishtmus itself actually means a small strip of land that has large bodies of water on either side, and it connects two larger land masses.
Panama is literary located on what could be defined as an ishtmus. The country is very narrow and elongated. On one side it is bordered by the waters of the Pacific Ocean, while on the other side it is bordered by the waters of the Caribbean Sea. It is located on the southernmost part of North America, touching South America, and being a natural land bridge between these two large land masses.