Which of the following is true when a plane intersects a cone to form a circle?
 A)The plane slices through a double cone and is perpendicular to the base of the cone.
 B)The plane slices through a single cone and is parallel to the base of the cone.
 C)The plane slices through a single cone and is at an angle parallel to the slanted edge of the cone.
 D)The plane slices through a double cone and is neither parallel nor perpendicular to the base of the cone.