A sanitary tee may be used to change the direction from which orientations?

A sanitary tee is a fitting used in plumbing systems to connect different sections of piping while allowing for changes in the direction of flow. Its primary function is to connect a vertical pipe to a horizontal pipe, facilitating a smooth transition for waste or drainage material.

In the context of this question, the key aspect of a sanitary tee is that it allows a vertical pipe (such as a stack for waste) to connect with a horizontal pipe (such as a drain line) at a 90-degree angle. This design helps prevent clogs and maintains optimal flow dynamics, ensuring that waste can exit the system efficiently.

While it might seem that a sanitary tee could also facilitate other orientations, it is generally designed and recognized primarily for the vertical-to-horizontal connection. Therefore, the most accurate understanding of the usage of a sanitary tee lies in its ability to change the direction specifically from vertical to horizontal. This focus on a standard and widely accepted application underscores why this answer is the most appropriate among the choices provided.