The answer is B. Isthmus.
An isthmus is a narrow strip of land that connects two larger land masses. It is typically surrounded by water on three sides, with the two larger land masses on either end. Isthmuses are important because they can provide a route for travel between two different land masses. For example, the Isthmus of Panama connects the North American and South American continents, and the Isthmus of Suez connects Africa and Asia.
A peninsula is a piece of land that is surrounded by water on three sides. It is typically connected to a larger land mass by a narrow strip of land. Peninsulas are important because they can provide a natural harbor for ships. For example, the Iberian Peninsula is home to the port city of Lisbon, Portugal.
A continent is a large land mass that is surrounded by water. There are seven continents in the world: Africa, Antarctica, Asia, Australia, Europe, North America, and South America. Continents are important because they are home to different cultures and ecosystems.
A gulf is a large, curved indentation of the sea that is surrounded by land on three sides. Gulfs are important because they can provide a natural harbor for ships. For example, the Gulf of Mexico is home to the port city of New Orleans, Louisiana.