Geometry

Question Analysis:
This question requires understanding the combination of properties.
Main focus: Condition that upgrades a rhombus to a square.

Key Concept Explanation:
A rhombus + 4 right angles = square.

Step-by-Step Solution:
Rhombus already has equal sides
Square adds 90° angles → D is correct

Option Analysis:
A) Already true for rhombus
B) True for many quadrilaterals
C) One angle ≠ square
D) Co...