Node.js Module System Mastery Hub: The Industry Foundation P

In the context of Node.js module resolution, what is the primary mechanism Node.js uses to locate and load modules, especially when dealing with relative paths and the `node_modules` hierarchy?

Consider a scenario where a module `A` requires module `B`, and module `B` requires module `C`. If module `C` is a singleton within the Node.js process, what is the expected behavior when module `A` also directly requires module `C`?

You are developing a large Node.js application and want to ensure that certain configuration settings are loaded only once and are accessible globally within your application's scope, similar to a singleton pattern. Which module system feature is most appropriate for achieving this, and how would you implement it?