Which type of vent connects directly to a fixture drain and terminates above the roof level?

The appropriate choice, which is the individual vent, is specifically designed to serve a single plumbing fixture. It connects directly to the fixture drain and extends vertically to a termination point above the roof level. This configuration is crucial because it allows for the venting of gases, helps maintain proper air pressure in the drain system, and supports the effective drainage of wastewater.

Individual vents are vital in preventing the siphoning of water from traps due to negative pressure created in the plumbing system. By venting above the roof, they also ensure that any gases released can disperse safely into the atmosphere, complying with building codes aimed at protecting both health and safety.

The other types of vents described, such as the main vent, common vent, and revent, serve different functions or configurations in plumbing systems. For example, main vents serve as a backbone for multiple fixtures, common vents connect two fixtures sharing a vent, and revents are essentially a type of vent that connects back to an existing vent system for additional support or airflow. None of these serve the singular purpose of directly connecting to a fixture drain as the individual vent does.