The correct answer is A. Caribbean Sea.
An island sea is a sea that is surrounded by islands. The Caribbean Sea is an example of an island sea. It is located between the Americas and the Caribbean Islands. The Caribbean Sea is a popular tourist destination, and it is also home to a number of important shipping routes.
The Caspian Sea is the largest inland body of water in the world. It is located between Europe and Asia. The Caspian Sea is not an island sea because it is not surrounded by islands.
The Red Sea is a sea located between Africa and Asia. It is connected to the Mediterranean Sea by the Suez Canal. The Red Sea is not an island sea because it is not surrounded by islands.
The Yellow Sea is a sea located between China and Korea. It is connected to the East China Sea by the Bohai Strait. The Yellow Sea is not an island sea because it is not surrounded by islands.