Which diagnostic tool includes multiple test options and can perform tests without an OS?

The Apple Service Diagnostic (ASD) is a comprehensive tool used by technicians to diagnose hardware issues on Mac computers. One of its key features is the ability to run multiple tests without requiring an operating system. This is critical in scenarios where the system is not bootable or has severe hardware failures, allowing technicians to independently assess hardware components such as memory, logic board, and storage drives.

In contrast, other diagnostic tools either require an operating system to function or are limited to specific types of tests. For example, Apple Hardware Test may only provide basic hardware checks and is not as extensive in testing options. Likewise, Apple Service Toolkit may not specifically cater to the broader range of hardware diagnostics without relying on an OS. Lastly, Apple Server Diagnostic is focused on server-related hardware and diagnostics, limiting its applicability compared to the broader capabilities of the Apple Service Diagnostic.

Hence, ASD stands out due to its capacity to perform a wide variety of tests directly, irrespective of the operating system's status.