The purpose of ETL isAll of the aboveCleaning dataRemoving redundancyNoneRemoving Null

The purpose of ETL (Extract, Transform, Load) is all of the above. ETL is a process that involves:

1. Extracting data from different source systems, which can be databases, CRM systems, files, etc.

2. Transforming it. This could involve cleaning data, which means removing errors, inconsistencies, and inaccuracies that could affect the results of data analysis. It could also involve removing redundancy, which means eliminating duplicate data to improve storage efficiency and data integrity. Another part of the transformation process could be dealing with null values, which could involve replacing them with other values or removing them entirely, depending on the specific requirements of the data analysis.

3. Loading it into a data warehouse or other system where it can be analyzed and used to generate insights.

So, the purpose of ETL is not just one of these options, but all of them.