The correct answer is option 4: Isthmus. An isthmus is a narrow strip of land that connects two larger land masses. It is usually surrounded by water on two sides, such as a sea or an ocean.
Option 1: A strait is a narrow passage of water that connects two larger bodies of water, such as two seas or two oceans. It does not connect two land masses directly.
Option 2: A peninsula is a piece of land that is surrounded by water on three sides. It is connected to a larger land mass by a narrow strip of land called an isthmus.
Option 3: A cape is a pointed piece of land that extends into a body of water, such as an ocean or a sea. It does not connect two land masses.
Therefore, the correct answer is option 4: Isthmus.