Which solution meets these requirements?

Explanations:

Enabling a Multi-AZ deployment provides high availability and durability by synchronously replicating data to a standby instance in another Availability Zone. This setup can achieve an RPO of less than 1 second due to the synchronous replication, ensuring minimal data loss in case of a failure.

Enabling auto scaling for the DB instance only allows for increased capacity during high load but does not improve the RPO. It does not provide any redundancy or replication that would minimize data loss in the event of a failure, thus failing to meet the requirement of an RPO of less than 1 second.

While creating read replicas can improve read scalability, they do not provide real-time data replication for writes. The replication from the primary instance to read replicas is asynchronous, which could lead to an RPO greater than 1 second in the event of a failure, failing to meet the requirement.

Using AWS Database Migration Service (AWS DMS) with change data capture (CDC) tasks can facilitate data replication, but it is primarily used for migration purposes rather than for achieving a low RPO in production systems. The latency involved in the CDC process may lead to an RPO that exceeds 1 second, making it unsuitable for this requirement.