A circle.
the base of a cylinder is a circle.
Technically you can not trace a sphere. If the base conditions are the same as for the other solid shapes, for example a cylinder, there is a base on which the cylinder rests, which creates the circle when it is traced. A sphere on a base would be touching in one point, which would be a dot. If you trace half a sphere, yes, than you do get a circle.
A prism. A prism is named for its base, eg a triangular prism has a triangle for the base. If the base is a circle, the circular prism is called a cylinder.
A circular plane surface
A cylinder is a tube with a base of a circle. A hexagon is a figure with a six sided base.
Circle
Strictly, if it has a circular base, it is a circular cylinder. Otherwise, it could have an oval base. If the long axis is at right angles (perpendicular) to the plane of the base, then it is a right circular cylinder.
The answer would be a right cylinder. A right cylinder is a cylinder that has a closed circular surface having two parallel bases on both the ends and whose elements are perpendicular to its base.
polyhedron
Sphere
Cylinder
The base