You have an ASP.NET Web Forms application for processing orders. Many users of the
application submit their order forms multiple times due to incorrectly formatted credit card
information. You need to plan for validation of the length and format of data in the credit
card field on the client side prior to processing each transaction. Which approach should
you recommend?

A.
Use a Required Field Validator control and a Compare Validator control.

B.
Use a Required Field Validator control and a Regular Expression Validator control.

C.
Use a Custom Validator control in the On Server Validate method

D.
Use a Custom Validator control in the Page_Load method.