What Is the Difference Between an Optical Double Star and a Visual

Multiple Choice

What is the difference between an optical double star and a visual binary star?

A) An optical double is an illusion-the stars are at vast distances from each other and are not actually orbiting each other-whereas in a visual binary, the stars are actually orbiting each other.
B) There is no difference-they are two names for the same thing.
C) The stars in an optical double star are actually orbiting each other, whereas a visual binary is an illusion-the stars are at vast distances from each other and are not actually orbiting each other.
D) Optical double stars can be seen as separate stars only through a telescope, whereas visual binaries can be seen with the unaided eye (e.g., the star Mizar in the Big Dipper's handle) .