You create a Web Form that contains a text box named txtDate. You want the text box to allow users to enter any valid date. You need to use an ASP.NET validation control to ensure that only valid date values are submitted to the server. What should you do? （）

Add a CompareValidator control to the Web Form. Set its ControlToValidate property to txtDate. Set its Type property to Date. Set its Operator property to DataTypeCheck.
B. Add a RangeValidator control to the Web Form. Set its ControlToValidate property to txtDate. Set its Type property to Date. Set its MinimumValue property to 01/01/1900 and its MaximumValue to the current date.
C. Add a CustomValidator control to the Web Form. Set its ControlToValidate property to txtDate. Write a function in the partial class that verifies the values as dates and returns a Boolean variable. Set the Custom Validators ClientValidationFunction to the name of your function.
D. Add a RegularExpressionValidator control to the Web Form. Set its ControlToValidate property to txtDate. Set the ValidationExpression property to ensure that the users input follows the format of nn-nn-nnnn, where n represents a number from 0 through 9.