Explanation
To enable vSAN ESA, two requirements that need to be met are: vSAN Standard license or higher, and vSAN ReadyNodes configuration. vSAN Standard license or higher is required to use vSAN ESA, as it is a feature that is only available in vSAN 8.0 or later versions. vSAN ESA is an optional, alternative architecture to vSAN OSA that is designed to process and store data with higher efficiency, scalability, and performance.
vSAN ReadyNodes configuration is required to use vSAN ESA, as it is a hardware configuration that is pre-configured, tested, and certified for VMware Hyper-Converged Infrastructure Software. Each vSAN ReadyNode is optimally configured for vSAN ESA with the required amount of CPU, memory, network, and storage NVMe devices. The other options are not correct. vSAN Build Your Own configuration is not supported for vSAN ESA, as it might not meet the hardware requirements or compatibility for vSAN ESA.
vSAN Witness Appliance is not required to use vSAN ESA, as it is only needed for stretched cluster or two-node cluster configurations. References: vSAN Express Storage Architecture; vSAN ReadyNode Hardware Guidance