Which of the following is an island sea?

Option B

The Caspian Sea is the world's largest inland body of water, variously classed as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau of Western Asia. It covers 371,000 km² (143,000 sq mi) (excluding the highly saline lagoon of Garabogazköl) and a volume of 78,200 km³ (19,000 cu mi)