Question

the red star is marking the body of water known as the
a baltic sea.
b north sea.
c bosporus strait.
d english channel.

Explanation:

By observing the location of the red - star on the map of Europe, the body of water it marks is the Baltic Sea. The Baltic Sea is located in Northern Europe, bordered by several countries including Sweden, Finland, Estonia, Latvia, Lithuania, Poland, etc.

Answer:

A. Baltic Sea