If we cut through the circle using the "fence" tool, the resulting shape should resemble the letter "C." However, the two points where the circle was cut, get connected to each other. This creates a new shape that should not appear and is not correct.
Using Trim Tool (2D Modification) you can get this .... Fence Tool preserves the original Geometry Type... if Arc is Clipped using Fence then Resultant Geometry will be Arc only and if Circle is Clipped then Resultant Geometry will be Complex Shape only