Geometry

Question Analysis:
This question asks for the exception among diagonal properties in parallelograms.
The main focus is on distinguishing general vs. special properties.

Key Concept Explanation:
In a general parallelogram, diagonals bisect each other but are not necessarily congruent.
Congruent diagonals occur in rectangles or squares.

Step-by-Step Solution:
Go through each statement and see if it holds for all parallelograms.
Option B (congruent diagonals) only applies to rectangles and squares.

Option Analysis:
A: Always true.
B: Not always true – correct answer.
C: Always true because of triangle co...