The DWV system of the dwelling should be tested with a minimum _______ head of water for ______.

The correct choice indicates that the drain, waste, and vent (DWV) system should be tested with a minimum head of water of 10 feet for a duration of 15 minutes. This requirement is based on plumbing codes and best practices, which are designed to ensure that the DWV system is functioning properly and will not allow for leaks or blockages.

A 10-foot head of water provides sufficient pressure to check the integrity of the system, simulating conditions that the plumbing would encounter under normal use. The 15-minute duration allows enough time for any potential leaks to become evident, as they may not be immediately apparent. This testing protocol helps confirm that all joints, connections, and materials of the DWV system can withstand the necessary pressure without leaking or failing.

Inadequate testing protocols, represented by the other options, either provide too low of a water head or an insufficient amount of time to detect faults properly, which may lead to undetected issues in the plumbing system that could result in future problems like leaks or sewage backup.