Question: IDSs can detect intruders by employing electromechanical systems or volumetric systems. Which of the following correctly describes these systems?
A. Because they detect changes in subtle environmental characteristics, electromechanical systems are more sensitive than volumetric.
B. Electromechanical systems are less sensitive than volumetric systems, which detect subtle changes in environmental characteristics.
C. Electromagnetic systems deal with environmental changes such as ultrasonic frequencies, while volumetric systems can employ pressure mats or metallic foil in windows.
D. Electromagnetic systems are more sensitive because they detect a change or break in a circuit, while volumetric systems detect environmental changes.

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