--- Catherine, I have cleaned the room for you．

       ---Thanks．You _______ it．I could manage it myself．

       A．needn’t do                                       B．shouldn’t  have done

       C．mustn’t do                                                                     D．needn’t have done

--- Catherine, I have cleaned the room for you．

       ---Thanks．You _______ it．I could manage it myself．

       A．needn’t do                 B．shouldn’t  have done

       C．mustn’t do                 D．needn’t have done

 --- Catherine, I have cleaned the room for you．

       ---Thanks．You _______ it．I could manage it myself．

       A．needn’t do                                       B．shouldn’t  have done

       C．mustn’t do                                                                     D．needn’t have done

 — Catherine, I have cleaned the room for you．

— Thanks, but you ________it．I could manage it myself．

       A．needn’t do                                   B．needn’t have done 

       C．mustn’t do                                    D．shouldn’t have done

．— Catherine, I have cleaned the room for you．

— Thanks, but you ________it．I could manage it myself．

       A．needn’t do   B．needn’t have done    C．mustn’t do   D．shouldn’t have done