Which of these fire extinguishers is best for putting out burning wires?

Which of these fire extinguishers is best for putting out burning wires?

• Carbon dioxide
• Sodium chloride
• Copper powder
• Foam 

EXPLANATION

If a small and contained fire breaks out – for example, if an extension cord begins to smolder -- you could successfully douse it with baking soda. That's right: baking soda, just like the kind you use in the kitchen. Baking soda contains sodium bicarbonate, which just happens to be the substance contained in Class C fire extinguishers, which are best suited for electrical fires. Baking soda produces water, which will effectively cool and smother a small fire.

Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive. Geometric symbol (blue circle)

CO2 extinguishers have an advantage over dry chemical extinguishers since they don't leave a harmful residue - a good choice for an electrical fire on a computer or other favorite electronic device such as a stereo or TV.