Which of the following allows for recovery without internet access?

The correct answer is Recovery HD. Recovery HD is a built-in partition on the Mac's hard drive that contains the necessary tools to diagnose and repair the operating system. Since it resides on the local storage of the Mac, users can access Recovery HD without requiring an active internet connection. This makes it particularly useful in situations where internet access is unavailable or unreliable.

The other options, while useful for various recovery scenarios, rely on different conditions. Internet Recovery, for instance, requires an active internet connection to download the recovery image from Apple's servers, making it not viable when offline. Command-S Recovery, which refers to starting up in single-user mode, is focused primarily on terminal-based diagnostics and filesystem repairs but doesn't provide the full suite of recovery tools available in Recovery HD. Safe Mode Recovery allows the system to boot with only essential extensions and services running, which can help troubleshoot issues, but again, it may not have the comprehensive recovery tools found in the Recovery HD.