Which aspect of a Standard Operating Procedure defines the extent of the procedure’s application?

The correct choice, which identifies the aspect of a Standard Operating Procedure (SOP) that defines the extent of the procedure’s application, is the scope. The scope section of an SOP clearly outlines the boundaries within which the procedure is applicable. It specifies what is included in the procedure, such as the departments, processes, or areas of activity it covers, and often indicates any limitations or constraints related to the procedure's use.

By detailing the application range, the scope helps users understand when and where the SOP should be utilized. This is crucial for ensuring the procedure is applied correctly and uniformly across relevant situations. In contrast, other sections such as definitions provide clarity on terminologies used, revisions refer to updates made to the document, and procedures outline the specific steps to be followed, but they do not define the extent of application like the scope does.