Final answer:
New water heaters use cathodic protection with sacrificial anodes like zinc or magnesium to prevent corrosion and extend their lifespan.
Step-by-step explanation:
The question relates to the type of technology used in new water heaters. While the options given may include various materials and safety features, the key to preventing corrosion in water heaters is a technique called cathodic protection. This method involves connecting the metal parts of the water heater, typically made of iron, to a more active metal like zinc or magnesium. These more active metals are known as sacrificial anodes and are used up as they corrode at the anode. By doing so, they protect the iron parts by serving as the cathode in the electrochemical process and thus extend the life of the water heater.