Answer:
Circles
Explanation:
Think of a soup can sitting on its base on a kitchen counter. The counter is an example of a plane (through) parallel to the base. The points where the can and counter intersect form a circle. Put a book on top of the can. Again, the plane of the book is parallel to the base and the book and can intersect in a circle.
The same thing would happen if you cut the can open with a plane anywhere in between the two mentioned above, but it would make a mess!