Answer: Option D.
Step-by-step explanation:
Here we see the cross-section of a cone when it is cut by a plane that is parallel to the base of the cone.
As the plane is parallel to the base, we expect to see a figure that has the same shape as the base ( a circle) (you can think that over the plane we have a smaller cone, and the base of that cone also must be circular)
So the correct option is D.
