Removing a DIMM (memory module) in Supermicro systems like the SYS-421GE-TNHR2-LCC requires only ESD gloves for safety;no additional toolsare needed. DIMMs are released by pushing down on slot latches and lifting out by hand, per Supermicro manuals (e.g., SYS-420GP-TNAR). A (pliers) risks damage, B (torque bit) and D (screwdriver) are for screws, not DIMMs. Supermicro's DLC systems maintain standard DIMM serviceability, making C correct.References:Supermicro DIMM replacement guides, DLC system maintenance standards.

The BMC (Baseboard Management Controller) cable and IO Module in Supermicro systems like the SYS-
421GE-TNHR2-LCC are often tied to add-on cards (AOC) within the PCIe tray. The AOC cage (likely an Add-On Card cage) must be removed first to access these components, as it houses cards and cables interfacing with the BMC. Supermicro's design (e.g., SYS-420 series) places AOC cages as sub-assemblies within the PCIe tray, requiring removal before deeper access. A (AOM cage) may be a typo or misidentification, B (BMC cage) isn't standard terminology here, and C (PCIe tray) is too broad since it's the parent assembly. D fits Supermicro's DLC service hierarchy, making it correct.
References: Supermicro PCIe tray sub-assembly guides, DLC system component access.

In Supermicro's SYS-421GE-TNHR2-LCC, the motherboard tray isbelow the PCIe tray, consistent with high-end server designs (e.g., SYS-420GP-TNAR). The motherboard tray houses CPUs and core components, while the PCIe tray (often with GPUs) sits above, connected via risers or direct slots. Options C and D reference a "GPU tray," likely a misnomer for the PCIe tray, but B remains accurate. Supermicro's DLC systems stack trays vertically for cooling efficiency, confirming B as correct.References:Supermicro chassis layout specs, DLC system tray configurations.