Which statement is correct regarding Data Transmission Service (DTS)?

The correct answer highlights that Data Transmission Service (DTS) can perform data migration between self-built Oracle databases, which reflects the service's versatility. DTS is designed to facilitate various data transmission tasks, including data migration, synchronization, and replication across different database types, including self-built Oracle databases. This capability makes DTS a powerful tool for users looking to manage data between on-premises and cloud or between different database platforms effectively.

DTS supports a range of database sources and targets, not limited to only MySQL or databases hosted on Alibaba Cloud. Therefore, its ability to handle migrations specifically between self-built Oracle databases illustrates its broad applicability.

The other choices reflect limitations that do not accurately describe DTS's functionality. For instance, DTS is not exclusive to MySQL databases, nor is it restricted to Alibaba Cloud-hosted databases. Furthermore, DTS does have the capability for real-time data synchronization, countering the claim that it cannot manage such tasks.