The correct answer is (a) Caspian Sea.
The Caspian Sea is a salt lake located between Europe and Asia. It is the largest lake in the world by surface area, and it is also the largest inland body of water in the world. The Caspian Sea has a salinity of about 1.2%, which is much lower than the salinity of the ocean, which is about 35%.
The Caspian Sea is a closed basin, which means that it does not have an outlet to the ocean. This means that the water in the Caspian Sea is not able to mix with the water in the ocean, and as a result, the salinity of the Caspian Sea is much lower than the salinity of the ocean.
The Caspian Sea is also a very shallow lake, with an average depth of only 17 meters. This shallowness makes it easier for the sun to evaporate the water from the lake, which also contributes to the low salinity of the Caspian Sea.
The Caspian Sea is home to a variety of fish species, including sturgeon, which are the source of caviar. The Caspian Sea is also a popular tourist destination, and it is home to a number of resorts.
The Caspian Sea is a unique and important body of water, and it is worth taking the time to learn more about it.
The other options are incorrect because they are all bodies of water that have a higher salinity than the Caspian Sea. The Dead Sea has a salinity of about 34%, the Mediterranean Sea has a salinity of about 38%, and the Red Sea has a salinity of about 41%.