You are designing a Windows Presentation Foundation (WPF) data entry application. The application uses data binding to bind controls in the user interface (UI) to business objects. The UI uses validation rules for each input control. The data validation rules change based on the state of the business object. You need to recommend a validation strategy that will allow changes to the validation rules without changes to the UI code.
What should you recommend?
A. Implement the IDataErrorlnfo interface in the business objects and replace all ValidationRule elements with ExceptionValidationRule elements.
B. Set the ValidationStep attribute on ValidationRule elements to CommittedValue.
C. Set the ValidationStep attribute on ValidationRule elements to RawProposedValue.
D. Implement the IDataErrorlnfo interface in the business objects and replace all ValidationRule elements with DataErrorValidationRule elements.
