Explanation/Reference:
A: A Service administrator manages administrative functions related to Oracle Cloud services within an identity domain.
D: The privileges given to the DBaaS Database Administrator role include:
Can scale, patch, and back up or restore database deployments
Incorrect Answers:
B: The privileges given to the DBaaS Database Administrator role are:
Can create and delete database deployments

Can scale, patch, and back up or restore database deployments

Can monitor and manage service usage in Oracle Cloud

C: Only identity domain administrators can manage user accounts, and they are allowed to add, modify, and remove user accounts only in the identity domains that they have been designated to administer.
References: https://docs.oracle.com/en/cloud/paas/database-dbaas-cloud/csdbi/service-roles-and- users.html