Which of the following is true of plumbing riser diagrams? a. Riser diagrams are plan view drawings b. Riser diagrams end at the terminal unit c. Riser diagrams illustrate both supply and return d. Riser diagrams illustrate the location/room where fixtures will be located e. Riser diagrams illustrate the entire path of water from the water main to individual fixtures, and back through the building sewer system to the sewer main