Geometry

Question Analysis：
This question asks which coordinate proof method best shows a figure is a rectangle.
Focus: using slopes (parallel and perpendicular) to prove.

Key Concept Explanation:
A rectangle must have:
Opposite sides parallel (equal slopes).
Adjacent sides perpendicular (negative reciprocal slopes or right angles).

Step-by-Step Solution：
Slope of AB: (0 - 0)/(4 - 0) = 0
Slope of BC: (3 - 0)/(4 - 4) = undefined
Slope of CD: (3 - 3)/(0 - 4) = 0
Slope of DA: (0 - 3)/(0 - 0) = undefined
Opposite sides have equal slopes (parallel), and adjacent sides are perpendicular (horizontal and vertical).

Option Analysis：
A) Congruent sides show rhombus, n...