A functional region is defined by a specific focal point and the surrounding areas that are influenced by it, often characterized by a specific function, such as economic activities, transportation routes, or communication networks.
Among the options provided, Silicon Valley would be classified as a functional region. It is centered around the technology and innovation industry, with surrounding areas that are economically connected to its tech-centric activities.
The other options (China, the Middle East, and Latin America) are more likely to be classified as formal regions based on shared cultural, political, or geographical characteristics rather than functional ones.