Which components are common in a wet pipe sprinkler system?

A wet pipe sprinkler system is characterized by the constant presence of water within the piping system. The correct choice highlights the essential components that work together to ensure that the system can effectively suppress a fire.

Sprinkler heads are critical as they are the devices that release water when the temperature exceeds a certain threshold, thereby activating the system. The piping is essential as it transports water from the supply to the sprinkler heads. Valves play a crucial role in controlling the flow of water and maintaining system pressure. Lastly, a reliable water supply is fundamental, as it ensures that there is an adequate source of water available to be delivered through the system when needed.

In contrast, options involving just piping and valves lack the inclusion of sprinkler heads and a water supply, which are necessary for a functioning wet pipe system. Components like a pumping station and water storage tank would typically belong to other systems or configurations, and a fire alarm system, while important for fire safety, serves a different function and is not part of the basic wet pipe sprinkler system architecture. Thus, the selection of all four necessary components in option B makes it the correct answer.