What are the important elements of the conclusion section in presentation?
选项：

A:a review of the topic and purpose of the presentation
B:a statement of the conclusions or recommendations to be drawn from your research work
C:an indication of the next stages (what might be done to take this work further)
D:an instruction as to what happens next (questions, discussion or group work)
E:a “thank you” to the audience for their attention and participation