Answer:
Sphere
Explanation:
Please refer to the attachment. Sphere is the 3D figure which when intersected by any plane , it will give us the circle. In attachment we see a red sphere of radius of 1. And the grey xy plane is intersecting the sphere which giving us the horizontal circle. Similarly yz and xz plane on intersecting gives two vertical circles. It is not just xy , yz, or xz plane but any plane when intersected to sphere gives a circle.
Hence our answer is Sphere