Explanation: CMOS (Complementary Metal-Oxide Semiconductor) devices are highly susceptible to damage from Electrostatic Discharge (ESD). Static electricity can build up on a person's body and, if discharged directly into sensitive components, can cause irreparable harm to their delicate internal structures. A wrist strap is an essential ESD protection device that safely grounds your body. It contains a series resistor (as specified by the question, less than 100,000 ohms, though 1 Megaohm is common) that provides a controlled, high-resistance path for static electricity to drain away slowly to ground. This controlled dissipation prevents a sudden, damaging spark that could harm the electronic components or pose a shock hazard to the user if they accidentally touch a live voltage while grounded. Option B is incorrect because while TTL (Transistor-Transistor Logic) devices are generally less sensitive than CMOS, they can still benefit from ESD protection. Option C is incorrect; while a water pipe can provide a ground, any proper earth ground or dedicated ESD ground point is suitable. Option D is incorrect; anti-static floor mats and wrist straps are complementary ESD protection tools designed to work together, not against each other.