英语选择—It is 18 o'clock and your father is still at the office．

英语选择—It is 18 o'clock and your father is still at the office．
—It is 18 o'clock and your father is still at the office．
—I know．Who else would ____ he does?
A．work so hard as B．be working harder than
C．do harder work than D．work as hard as
到底选哪一个