What type of numbers can be found in the lower right corners of some sheets?

The correct answer, which identifies the type of numbers found in the lower right corners of some sheets as drawing index numbers, is based on the functionality and organization of construction documents. Drawing index numbers serve as unique identifiers that allow for easy reference to specific drawings or plans within a set. They help in maintaining an organized and systematic approach to managing a large volume of documents within a project. This is essential during both the review and construction phases, as stakeholders can quickly locate the necessary drawings by referencing these indices.

In contrast to the incorrect options, other types of numbers such as page references, construction project numbers, or material designations do not typically occupy that specific location on the sheets. Page references may appear in other contexts but are not specifically designated for use in the bottom right corner of construction drawings. Construction and project numbers have different uses and are generally not placed in that same format, while design material numbers would more likely be cataloged in specifications or material lists rather than on the actual drawings. Thus, the presence of drawing index numbers in the lower right corner emphasizes the efficient navigation and identification of drawings in construction documents.