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) .