Which of the following materials would likely require cathodic protection?

Cathodic protection is a technique used to prevent corrosion of metal surfaces, typically in buried or submerged conditions. Metal pipes, as they are conductive and prone to corrosion when in contact with moisture and electrolytes in the soil or water, are at significant risk. This corrosion can lead to structural failure and leaks, which is why implementing cathodic protection is critical for maintaining the integrity and lifespan of metal pipes used in water distribution systems.

The other materials listed, such as plastic, glass, and ceramic, are non-conductive and do not corrode in the same way that metals do. Plastic pipes, for example, are resistant to most types of corrosion and are commonly used for their durability in various environments. Glass pipes also do not corrode and are primarily used where chemical resistance is needed. Similarly, ceramic pipes are valued for their strength and resistance to degradation. None of these materials require cathodic protection because they do not experience the same electrochemical corrosion processes as metal pipes.