Geometry

Question Analysis:
This question requires comparing properties across three quadrilaterals.
The main focus is identifying the unique shared feature of squares and rhombuses that rectangles don't possess.

Key Concept Explanation:
Squares and rhombuses: Both have all four sides equal
Rectangles: Only require opposite sides to be equal (not all four)
Shared properties of all three:
Opposite sides parallel (A)
Diagonals bisect each other (B)
Unique to squares/rectangles:
Equal diagonals (D)

Step-by-Step Solution:
Eliminate A and B (shared by all three shapes)
Eliminate D (only squares and rectangles have equal diagonals)
Confirm C is correct (rectangles don't require all sides equal)<...