According to the Oracle Cloud Guard documentation1, Cloud Guard is a cloud native service that helps customers monitor, identify, achieve, and maintain a strong security posture on Oracle Cloud. Use the service to examine your Oracle Cloud Infrastructure resources for security weakness related to configuration, and your Oracle Cloud Infrastructure operators and users for risky activities. Upon detection, Cloud Guard can suggest, assist, or take corrective actions, based on your configuration.

Therefore, option A and option E are correct ways that Cloud Guard helps improve the overall security posture for your tenancy. Option B is incorrect because Cloud Guard does not allow you to centrally manage encryption keys. That is the function of the Vault service2. Option C is incorrect because Cloud Guard does not prevent you from creating misconfigurations on your resources in OCI. It only detects and reports them, and optionally takes corrective actions. Option D is incorrect because Cloud Guard does not mask sensitive data and monitor security controls on your Oracle databases. That is the function of the Data Safe service3.

Oracle Security Zones is a service that helps you enforce best practices and prevent misconfigurations on your OCI resources by applying predefined policies and controls. Some of the benefits of using Security Zones are:

• Encrypt storage resources with a customer-managed key: Security Zones require that all storage resources, such as block volumes, boot volumes, file systems, and object storage buckets, are encrypted with a customer-managed key from Vault. This ensures that you have full control over the encryption and decryption of your data at rest.
• Deny public access to OCI resources, such as databases and object storage buckets: Security Zones prevent you from creating or updating OCI resources that have public access enabled, such as databases and object storage buckets that are accessible from the internet. This reduces the risk of unauthorized access or data leakage.

Exadata Virtual Machine is not a valid option for an OCI compute shape. Exadata Virtual Machine is a deployment option for Exadata Cloud Service or Exadata Cloud@Customer, which are services that provide dedicated Exadata infrastructure for running Oracle databases in OCI. Exadata Virtual Machine allows you to create multiple virtual machines on each Exadata compute node and isolate them from each other using Oracle VM technology. The valid options for OCI compute shapes are:

• Bare Metal: A bare metal instance is a physical server that gives you direct access to the underlying hardware and full isolation from other tenants.
• Dedicated Virtual Machine Host: A dedicated virtual machine host is a physical server that hosts only your virtual machine instances and no other tenant’s instances.
• Virtual Machine: A virtual machine instance is a virtual server that runs on a shared physical server with other tenants’ instances.
• Burstable: A burstable instance is a virtual machine instance that has a baseline utilization of either 12% or 50% of each CPU core and can burst above the baseline when needed.