Geometry

Question Analysis：
This question tests the relationship between parallelograms and special quadrilaterals (rectangles).
The main focus is recognizing that a parallelogram with one right angle implies all angles are right angles.

Key Concept Explanation:
A rectangle is a parallelogram with four right angles.
In a parallelogram, if one angle is 90°, all consecutive angles are 90° (supplementary), making all angles right angles.

Step-by-Step Solution：
In a parallelogram, consecutive angles are supplementary.
If one angle is 90°, its consecutive angle is 180° - 90° = 90°.
By opposite angle congruence, all angles are 90°, defining a rectangle.

Option Analysis：
A) Incorrect. A rhombus has congruent sides but not necessarily righ...