NCIDQ Interior Design Professional Exam (IDPX) Practice Exam

The choice indicating "all of these" is correct because all of the mentioned fixtures – shower drains, toilets, and mop sinks – are typically connected to a plumbing trench. A plumbing trench serves as a channel to house the drainage pipes for these fixtures, ensuring that waste water is efficiently directed away and properly managed.

Shower drains require direct access to the plumbing for effective drainage and to avoid any potential backups. Toilets are crucial components that must also be aligned with plumbing lines to function correctly since they rely on gravity for flushing waste through a sewer line. Likewise, mop sinks, which are used for cleaning and managing water usage in a variety of environments, need to be plumbed into the same system to ensure that wastewater is appropriately disposed of.

Thus, all these items benefit from being located on a plumbing trench, which is designed to accommodate them and facilitate proper drainage and efficiency.