请选择ABCD:?.L1S,d4b6w'L I was just about _________ the office when the phone rang..Y*m8~1p7C7i3u2b-h0P
A.leaving.Y*m8~1p7C7i3u2b-h0P
B.leave.Y*m8~1p7C7i3u2b-h0P
C.to leave.Y*m8~1p7C7i3u2b-h0P
D.to leaving.Y*m8~1p7C7i3u2b-h0P