Duplicate data in multiple data files is:

The correct answer is data redundancy, which refers to the unnecessary duplication of data within a database or data storage system. In the context of information technology, data redundancy can lead to several issues such as increased storage costs, difficulties in maintaining data integrity, and challenges in data management. When the same data appears in multiple files, it can result in discrepancies if the data is updated in one location but not in others, which complicates keeping the data consistent and could potentially create errors in reporting and analysis.

On the other hand, data independence pertains to the capacity to change the schema at one level of a database system without having to change the schema at the next higher level, and it does not relate to the presence of duplicated data. Data multiplication is not a recognized term in the context of data organization or management, and while data backups are essential for data recovery and preservation, they serve a different purpose and do not inherently involve duplication in the sense of redundancy.