Among the following fixtures, which has the greatest water pressure?

The water closet typically has the greatest water pressure among the fixtures listed. This is primarily due to the design and operational requirements of the toilet. Water closets need a significant amount of pressure to efficiently flush waste down the drain. The flushing mechanism relies on a powerful rush of water, which is often facilitated by higher water pressure to ensure effective operation.

While faucets and showers also rely on water pressure to function, they are generally designed for lower volume flow rates compared to water closets. Faucets may provide adequate pressure for washing hands, while showers typically create a pleasant experience without needing the kind of water pressure that a toilet demands during a flush.

In contrast, stating that all fixtures have equal pressure doesn't accurately reflect the differing requirements and functions of each fixture. Each one is engineered for its specific purpose, resulting in varying water pressure levels.