A company is using Amazon RDS.

The customer is responsible for selecting and configuring the encryption options used for its Amazon RDS database. When creating an encrypted DB instance, the customer enables encryption and can select an AWS managed KMS key or an eligible customer managed KMS key. The customer must also manage permissions and policies for customer managed keys. Therefore, option A is correct. Amazon RDS is a managed database service, so AWS manages the underlying server hardware and the operating system used to run standard RDS DB instances. RDS also manages routine database software patching, including applicable minor-version maintenance according to the configured maintenance and upgrade settings. The exact division can differ for specialized products such as RDS Custom or engines enrolled in Extended Support, but the foundational-level question refers to standard Amazon RDS. AWS protects and maintains the managed infrastructure, while customers remain responsible for their data, database users, access controls, network configuration, encryption choices, application integration, and query tuning. The exam clue is that encryption is a customer security configuration decision, whereas physical hardware and underlying managed-platform patching are handled by AWS.