— 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