When you slice a cone horizontally, you create a cross-section that results in a circle. If you're cutting the cone at different heights, you would typically see two circles: one for the top of the cone and one at the height of the cut, with the top circle being smaller than the larger one at the base. However, if we consider the response options given, the most correct answer, if we interpret "slicing a cone horizontally" as slicing through at two different levels, would be:
two circles, with one larger than the other.