Geometry

Question Analysis
This question involves differentiating frustums from complete cones.
The main focus is on structural features.

Key Concept Explanation
Frustum: Created by slicing a cone parallel to the base → Results in two parallel circles (top and bottom).
Full cone: Only one circular base + apex.
Both can be right/oblique (not unique to frustums).

Step-by-Step Solution
Eliminate A (all cones have circular bases).
Eliminate C (full cones have apexes; frustums lose the original ap...