Geometry

Question Analysis:
This question tests knowledge of the fundamental properties of parallelograms.

Key Concept Explanation:
A parallelogram is a quadrilateral with:
Opposite sides parallel and congruent.
Opposite angles congruent (not supplementary).
Diagonals that bisect each other (but are not necessarily equal).
Adjacent angles that are supplementary.

Step-by-Step Solution:
Recall the properties of parallelograms.
Evaluate each option:
A) False (Diagonals are equal only in rectangles).
B) False (Opposite angles are equal, not supplementary).
C)...