Click the Exhibit button.  Given the web application deployment descriptor elements： 11. 12.ParamAdder 13.com.example.ParamAdder 14.... 31. 32.ParamAdder 33.Destination 34.... 55. 56.Destination 57./dest/Destination 58. What is the result of a client request of the Source servlet with no query string？（）

• A、The output "filterAdded = null" is written to the response stream.
• B、The output "filterAdded = addedByFilter" is written to the response stream.
• C、An exception is thrown at runtime within the service method of the Source servlet.
• D、An exception is thrown at runtime within the service method of the Destination servlet.