当然选C.
你肯定是这样想的,前面是would you mind doing sth,介意做某事,然后你就回答,not at all,一点也不（介意) ,其实英语中的交际用语与中文不同,这里其实是有点责怪或劝说,命令的意思了,就像一句,Jim,please don't run in the hallways,---Sorry,Miss Liu,I won't.,would you mind只不过比don' do sth 委婉地说法,意思差不多,反正英语当中,随时随地都在sorry,thank you!