You work as an application developer at Certkiller .com. You have recently created an application that includes the code shown below. public delegate stringGetFileContentsDel （）； public string GetFileContents （） {  //Process file and return results }  You now need to invoke the GetFileContents method asynchronously.  You have to ensure that the code you use to invoke the GetFileContents method will continue to process other user instructions， and displays the results as soon as the GetFileContents method finishes processing.What should you do？（）

• A、A
• B、B
• C、C
• D、D