The correct option is Availability Zones.

Availability Zones are distinct fault domains inside a cloud region and they are used to place replicas in separate physical locations to reduce the impact of a single zone failure and to improve overall availability. When provisioning a NebulaDB account the capability to select availability zones is what ensures replicas are distributed across multiple zones within the same region so that an outage in one zone will not take down all replicas.

Multi-master replication refers to a replication topology that allows multiple nodes to accept writes and it addresses write availability and conflict handling. It does not by itself specify how replicas are placed across physical zones so it is not the correct choice.

Regional Persistent Disk is a block storage feature in some cloud providers that replicates data across zones for durability and failover. It is a storage level feature and not the database provisioning capability that controls where NebulaDB places its replicas, so it is not the correct answer.

Strong consistency model describes the guarantees about read and write ordering across replicas and it affects correctness of data access. It does not determine the physical distribution of replicas across availability zones and therefore it is not the right option.

Full AWS Practitioner Certification Question