An administrator is logged into Data Loader with their own credentials to insert new Business...

When using Data Loader to insert new records into Salesforce,if the Account Owner field is not specified in the import file, the default owner will be the user who is logged into Data Loader. In this case, since the administrator is logged into Data Loader with their own credentials, they will be assigned as the owner of all the new Business Account records. This behavior is consistent with the standard Salesforce rule that every record must have an owner.