Đáp án: A
Hardly I had (A) got onto the motorway when (B) I saw (C) two police cars following (D) me.
Công thức: Hardly + had + S + Ved/ V3 when + S + Ved/ V2: ngay khi... thì...
I had => had I
Hardly had I got onto the motorway when I saw two police cars following me.
Tạm dịch: Ngay khi tôi đi lên đường cao tốc thì tôi thấy hai chiếc xe cảnh sát theo sau tôi