一个较难的高中英语单选题----高手帮忙
28、—I wonder if you could go to the movie with me.
—Oh,just leave me alone.I _____ a composition all the morning and haven’t finished yet.
A：write B：was writing C：have written D：have been writing
【考查知识点】时态
【译】
请按照要求回答,