Which sentence is the correctly written compound sentence?
 a. The Statue of Liberty is located on a small, uninhabited island called Liberty Island.
 b. Liberty Island is a small, uninhabited island where the Statue of Liberty is located.
 c. Liberty Island is a small, uninhabited island, it is best known as the location of the Statue of Liberty.
 d. Liberty Island is a small, uninhabited island, but it is best known as the location of the Statue of Liberty.