A fault domain is a grouping of hardware and infrastructure within an availability domain.
Fault domains provide anti-affinity: they let you distribute your instances so that the instances are not on the same physical hardware within a single availability domain.
To control the placement of your compute instances, bare metal DB system instances, or virtual machine DB system instances, you can optionally specify the fault domain for a new instance or instance pool at launch time.

With Autonomous Database on shared Exadata infrastructure, you do not need to configure or manage any hardware or install any software. Autonomous Database handles provisioning the data-base, backing up the database, patching and upgrading the database, and growing or shrinking the database. Autonomous Database is a completely elastic service.An autonomous database is a cloud database that uses machine learning to automate database tuning, security, backups, updates, and other routine management tasks traditionally performed by DBAs.

Oracle Database Service for Azure (OracleDB for Azure) is an Oracle managed service delivering Oracle Database services in Oracle Cloud Infrastructure (OCI) directly to Microsoft Azure custom-ers through the OCI Azure Interconnect (a capability available between the two cloud environments in regions located around the world).
OracleDB for Azure uses a service-based approach, and is an alternative to manually creating complex cross-cloud deployments using the Interconnect.

Log Analytics Workspace, Application Insights and Custom Dashboard are Azure resources and hence we can eliminate these options.
We are left with Oracle Database Service which is the CORRECT answer.