| Concerning pressure-relief valves, what statement is true? |
| A) No stop isolation valve may be installed between the relief valve and its source of pressure, and no stop isolation valve may be installed in the relief valve discharge piping. |
| B) It is permissible to install a stop isolation valve between the relief valve and its source of pressure, but no stop isolation valve may be installed in the relief valve discharge piping. |
| C) It is permissible for a stop isolation valve to be installed between the relief valve and its source of pressure, and it is permissible for a stop isolation valve to be installed in the relief valve discharge piping. |
| D) No stop isolation valve may be installed between the relief valve and its source of pressure, but it is permissible for a stop isolation valve to be installed in the relief valve discharge piping. |
