During the implementation of a new application, data from the old system will have to be converted and migrated to the new system. One of the greatest risks is the lack of data transformation rules. These rules are crucial for ensuring that the data from the old system can be accurately and effectively used in the new system. They define how data in the old system is mapped to the new system, how data quality issues are managed, how data types or formats are converted, and other similar aspects.

Answer D - data conversion process must provide some means, such as audit trails and logs, to allow for the verification of the accuracy and completeness of the converted data. This verification of accuracy and completeness may be performed through a combination of manual processes, system utilities, vendor tools and one-time-use special applications.

The greatest risk associated with data conversion and migration during the implementation of a new application is typically option C, "Obsolescence and data backup compatibility." Obsolescence and data backup compatibility refer to the risk that the data being migrated may become incompatible with the new application or storage systems due to changes in technology or formats over time. This can result in the loss or corruption of data during the migration process, leading to significant operational disruptions, data loss, and potentially compliance issues. While lack of data transformation rules (option A) is also a significant risk, having obsolete or incompatible data backups poses a more immediate and critical threat to the success of the data conversion and migration process. Therefore, obsolescence and data backup compatibility represent the greatest risk in this context.

While Option C, "Obsolescence and data backup compatibility," presents significant challenges during the migration process, its impact might be more limited to the migration phase itself, especially if effectively addressed. In contrast, inadequate logging can have enduring consequences that extend beyond the migration phase, affecting data integrity, troubleshooting, compliance, and overall system reliability throughout the application's lifecycle.

A is answer.

this should be C