A. Have you written / have just finished / have been doing
Feedback 1,2. We use the Present Perfect to emphasize the result. 3. We use the Present Perfect Continuous to emphasize the duration of some action which started in the past and continues up to now.
B. Did you write / have just finished / have been doing
C. Have you written / have just finished / have done
D. Have you written / just finish / have been doing