Explanation
A service interface is a logical interface on a tier-0 gateway that connects to a VLAN logical switch and provides NSX Edge services to the VMs on that switch. A service interface is required for services such as load balancing, VPN, NAT, and DHCP1. A downlink interface is used to connect a tier-0 gateway to a tier-1 gateway or an overlay logical switch. A VLAN uplink is used to connect a tier-0 gateway to the physical network. A loopback router port is used to assign an IP address to the tier-0 gateway for routing protocols or firewall rules2...

Explanation
NAT64 is a type of NAT that allows IPv6-only hosts to communicate with IPv4-only hosts by translating the IPv6 addresses to IPv4 addresses and vice versa.
C: NAT64 is supported on Tier-0 and Tier-1 gateways. This is stated in the first result1, which says
"Three types of NAT are supported, in addition to NAT64."
E: NAT64 requires the Tier-1 gateway to be configured in active-active mode. This is implied by the third result2, which says "Stateful NAT is not supported in active-active mode." Since NAT64 is stateless, it can be supported in active-active mode.

Explanation
According to the VMware NSX Documentation, a non-preemptive failover policy means that the original failed node will not become the active node upon recovery, unless the current active node fails again. This policy can help avoid unnecessary failovers and ensure stability.
The other options are either incorrect or not available for this configuration. Preemptive is the opposite of non-preemptive, meaning that the original failed node will become the active node upon recovery, if it has a higher priority than the current active node. Enable Preemptive and Disable Preemptive are not valid options for the failover policy, as the failover policy is a drop-down menu that only has two choices: Preemptive and Non-Preemptive.

Explanation
To generate the support bundle logs on the NSX Manager via API, the NSX administrator needs to use the POST method with the URL https://nsxmgr_ip/api/1.0/appliance-management/techsupportlogs/NSX, where nsxmgr_ip is the IP address of the NSX Manager1. This will create a tech support bundle file with a name like vcpnv.tgz. To download the generated tech support bundle file via CLI, the NSX administrator needs to use the get support-bundle file vcpnv.tgz command on the NSX Manager1. The other commands are incorrect because they either do not generate or download the support bundle logs, or they are not related to the NSX Manager.

Explanation
According to the VMware NSX Documentation, Switch Visualization is a feature in the NSX UI that shows the mapping between the virtual NIC and the host's physical adapter for virtual machines running on an ESXi transport node. You can use Switch Visualization to view details such as port ID, MAC address, VLAN ID, IP address, MTU, port state, port speed, port type, and port group for each virtual NIC and physical adapter.
https://docs.vmware.com/en/VMware-NSX/4.1/installation/GUID-55E5C735-18AD-43F8-9BE5-F75D5B8C6ED