To provide highly available access specifically to Grid Manager and Tenant Manager, the HA group must contain Admin Node interfaces. StorageGRID 12.0 documentation states that Admin Nodes provide access to these management services, whereas Gateway Nodes provide the Load Balancer service for S3 client traffic.
For Grid Manager access, the HA group should contain the primary Admin Node and one or more non- primary Admin Nodes; the primary Admin Node must be configured as the primary interface in the group.
Tenant Manager also runs on Admin Nodes. Tenant users connect to an Admin Node when accessing Tenant Manager, so using multiple Admin Node interfaces behind an HA virtual IP provides the required management-interface availability.
Option B is incorrect because Gateway Nodes do not provide Grid Manager or Tenant Manager. Option D is valid for S3 client access, because both Admin and Gateway Nodes run the Load Balancer service, but it is not the correct configuration for management-interface HA. Option C corresponds to a specialized HA configuration used for S3 Select and does not satisfy the management-service requirement.
Therefore, the correct answer is A.
Reference topics: Grid Manager # High Availability Groups # Administrative Connections # Admin Nodes # Grid Manager/Tenant Manager # VIP Failover