Explanation
To enable a virtual machine to power on with a PCI graphics accelerator, such as a GPU, attached to it, the administrator needs to reserve all guest memory for that virtual machine. This is because PCI devices require direct memory access (DMA) to function properly, and memory overcommitment can interfere with DMA operations. Reserving all guest memory ensures that no memory swapping or ballooning occurs on the virtual machine, and that the memory address space is contiguous and available for DMA56.
The other options are not required or valid because:
Enabling Video Card 3D Graphics is not necessary for using a PCI graphics accelerator. This option is for using software-accelerated graphics or virtual shared graphics acceleration (vSGA) on a virtual machine7.
Setting Memory Shares to High does not guarantee that all guest memory will be reserved. Memory shares only affect how memory resources are distributed amongcompeting virtual machines when there is memory contention on the host. Memory shares do not prevent memory overcommitment or swapping.
Disabling CPU Hot Plug does not affect the use of a PCI graphics accelerator. CPU Hot Plug allows adding or removing virtual CPUs from a powered-on virtual machine. It has no relation to PCI devices or DMA operations.
References := 5: VMware vSphere 7 Documentation: Add a PCI Device to a Virtual Machine 6: VMware Knowledge Base: Enabling DirectPath I/O causes virtual machines to fail to power on (1010789) 7: VMware Workstation Pro Documentation: Prepare a Virtual Machine to Use Accelerated 3D Graphics : VMware vSphere Resource Management Documentation: Memory Resource Management : VMware vSphere Virtual Machine Administration Documentation: Hot Add Memory and CPU Resources