Option A is the correct choice for implementing a data archiving solution. Amazon S3 is a highly scalable and durable object storage service that can store large amounts of data for long-term archiving. By using S3 Lifecycle policies, you can automatically transition data to S3 Glacier, which is designed for long-term archiving and provides secure, durable, and cost-effective storage. This approach meets the requirements for long-term storage and occasional access for compliance or analytical purposes. While other options like RDS, Redshift, and DynamoDB have their use cases, they may not be as suitable for the specific needs of long-term archiving and occasional access.