— How long _____ at this job ?

— Since 1990.   

A. were you employed          B. have you been employed

C. had you been employed       D. will you be employed

--How long        at this job?

    --Since 1990.

    A. were you employed                B. have you been employed

    C. had you been employed            D. will you be employed

---- How long ____ at this job?

    ---- Since 1990.

A. were you employed           B. have you been employed

C. had you been employed        D. will you be employed

---- How long ____ at this job?

   ---- Since 1990.

A. were you employed      B. have you been employed

C. had you been employed   D. will you be employed

. ---- How long ____ at this job?

   ---- Since 1990.

A. were you employed      B. have you been employed

C. had you been employed   D. will you be employed