You create a Windows application by using the .NET Framework 3.5.
The application has a complex form that is used to capture information.
Users of the application enter data in the forms quickly by using tabs to navigate through the form controls.
They must be immediately notified when they enter invalid data in the form controls.
You need to notify the users without blocking the data entry process.
Which control should you use?

A.
MessageBox

B.
HelpProvider

C.
ErrorProvider

D.
ToolTipProvider