Which of the following best describes signed languages?

The best description of signed languages is that they use visual signs made with the body, hands, and face. This highlights the fundamental nature of signed languages as fully developed languages that rely on visual-spatial modalities for communication rather than auditory ones. Signed languages are rich, complex systems of communication that incorporate not only hand shapes and movements, but also facial expressions and body postures, which are all integral to conveying meaning effectively.

In contrast, other options either misrepresent the nature of signed languages or oversimplify them. Signed languages do not depend on spoken words or audio cues, which is a critical distinction, as they function independently. Additionally, while some individuals may use both signed and spoken languages together in specific contexts, this doesn't define signed languages themselves; they're distinct language systems. Furthermore, the claim that signed languages are simplified versions of spoken languages fails to recognize their complexity and cultural richness. It's essential to appreciate signed languages as proper, autonomous linguistic systems with their own grammar and structure, equivalent in complexity to spoken languages.