Q: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Two of the four circles that can be drawn at any point on this shape are named for Villarceau. An integrable Hamiltonian system can only move on a surface with this shape according to the Kolmogorov-Arnold-Moser theorem. Like the Klein bottle, it has an Euler characteristic of zero. At most, seven colors are used be used to color a map of this shape, according to the Heawood conjecture. Its surface area equals four pi squared times the product of the inner and outer radii. It is topologically defined as the product of two circles. For 10 points, name this three-dimensional surface shaped like a doughnut.
A:
Science