Which of the following are primary components of a plumbing system?

The primary components of a plumbing system are best represented by supply pipes, drainage pipes, fixtures, and valves. Supply pipes are essential as they transport potable water from a source to various fixtures throughout the building, such as sinks and toilets. Drainage pipes play a crucial role as they carry wastewater away from these fixtures to the sewer or septic system, ensuring proper sanitation and waste disposal.

Fixtures refer to the devices installed at the endpoints of the supply lines, such as faucets, toilets, and showers, that users interact with directly. Valves are critical for controlling the flow of water within the system, allowing for shut-off capabilities and pressure regulation. Together, these components form the backbone of a plumbing system, facilitating the safe and efficient movement of water.

The other options include components unrelated to plumbing systems. Filters, ladders, air ducts, electrical wires, and various types of cables are part of other systems like HVAC or electrical setups but do not fall within the primary scope of plumbing. Understanding these core components helps in comprehending how plumbing systems are designed, installed, and maintained.