B. Access controls that are not adequate to prevent data modification
Once the data is in a warehouse, no modifications should be made to it and access controls should be in place to prevent data modification. Increased response time on the production systems is not a risk, because a data warehouse does not impact production data. Based on data replication, data duplication is inherent in a data warehouse. Transformation of data from operational systems to a data warehouse is done at predefined intervals, and as such, data may not be current.