Which of the following illustrates the explanation for the symbols used on drawings?

The correct choice is the legend because it serves as a key that explains the symbols, icons, and abbreviations used in technical drawings, such as electrical schematics. A legend provides clarity and understanding to anyone reviewing the drawings, ensuring that they can interpret the representations accurately.

In the context of architectural or engineering drawings, a legend includes details like what each symbol means, such as circuit breakers, outlets, and wiring types. This helps avoid confusion, especially when multiple symbols are presented within a single drawing.

While an index lists topics or items found within a document and a glossary defines specialized terms, they do not specifically focus on explaining the symbols. A reference chart may offer additional information related to measurements or standards but does not serve the same purpose as a legend in terms of symbol identification. Therefore, the legend is essential for effective communication in technical drawings and is crucial for proper understanding and implementation of the electrical plans.