Geometry

Question Analysis
This question involves predicting geometric changes from truncation.
The main focus is on frustum formation.

Key Concept Explanation
Truncation effect:
Adds a parallel smaller circle at the cut.
Original base remains unchanged.
Slant height changes (new trapezoidal cross-section).

Step-by-Step Solution
Eliminate A (bases retain circularity).
Eliminate B (slant height is now the trapezoid's non-parallel side).
Eliminate D (truncatio...