Geometry

Question Analysis:
The question tests your ability to detect a curved-surface shape hidden among pyramids.
Main focus: Flat vs. curved sides and polygonal base.

Key Concept Explanation:
Pyramids always have flat triangular faces and polygonal bases.
Curved surfaces = not a pyramid.

Step-by-Step Solution:
A: Square base + triangle sides → pyramid
B: Circle base + curved side → cone
C: Pentagon base + triangle sides → pyramid
D: Rectangle base + triangle sides → pyr...