Which of the following 3D shapes does not have a vertex?

Option (a) The point at which two or more edges meets is called vertex. Pyramid has atleast 4 vertices.

(b) The point at which two or more edges meets is called vertex. Prism has atleast 6 vertices.

(c) The point at which two or more edges meets is called vertex. Cone has one vertex.

(d) The point at which two or more edges meets is called vertex. Sphere does not have any vertex and edge.