What is a 3-D solid with 0 faces 0 edges and 0 corners?

Answer 1

Some might suggest a point in 3-D. But the fact that it is in 3-D space does not make it a 3-D solid. A point is not a 3-D solid in the same way that a straight line in 3-D space is a linear (1-D object) and not a solid.

A sphere is a possibility in the sense that it clearly has no edges or corners and, if a face is defined as a PLANE surface, then a sphere has none. But in that case you need to include ellipsoids, torus (doughnut shapes), etc as well.

Furthermore, the question says nothing about the solid being finite in extent. So paraboloids and hyperboloids would also qualify.