In which ETL stage would a business intelligence professional map data types from the sources to the target system in order to ensure the data fits the destination?

Q: In which ETL stage would a business intelligence professional map data types from the sources to the target system in order to ensure the data fits the destination?

or

Q: To make sure the data meets the destination, what ETL stage would a business intelligence specialist map data types from the sources to the target system?

• Load
• Extract
• Transform 
• All three stages involve this step

Explanation: In the Transform stage of the ETL process, a business intelligence professional maps data types from the sources to the target system to ensure the data fits the destination. This stage involves converting the data into a suitable format and structure for the target system, including data type mapping and other transformations.