A: With advanced data preparation available in Power Apps, you can create a collection of data called a dataflow, which you can then use to connect with business data from various sources, clean the data, transform it, and then load it to Microsoft Dataverse or your organization's Azure Data Lake Gen2 storage account.
B: By combining conditions and actions, you can do any of the following with business rules:
Set column values
Clear column values
Set column requirement levels
Show or hide columns
Enable or disable columns
Validate data and show error messages
Create business recommendations based on business intelligence.
C: Duplicate detection works by comparing generated match codes of existing records with each new record being created. These match codes are created as each new record is created. Therefore, there is potential for one or more duplicate records to be created if they are processed at the exact same moment. In addition to detecting duplicates as they are created, you should schedule duplicate detection jobs to check for other potential duplicate records.
Reference:
https://docs.microsoft.com/en-us/powerapps/maker/data-platform/data-platform-create-business-rule
https://docs.microsoft.com/en-us/powerapps/maker/data-platform/create-and-use-dataflows
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/duplicaterule-entities