A Researcher Presents the Results of a Recent Research Project

A researcher presents the results of a recent research project at several conferences. Duplicate publications are not acceptable and represent self-plagiarism, but duplicate presentations seem valued. Which of the following facts explains this?

A) Duplicate conference presentations are valued only when they occur in widely separated geographic areas.
B) Questions and comments from conference audiences can contribute to the researcher's ongoing analysis and inspire new analyses of data.
C) If similar research by the same author is ongoing, each conference presentation can include new insights and interpretations, reflecting work in progress.
D) Reaching a broad audience necessitates presentation at several conferences.
E) Self-plagiarism is a term that refers to the printed word, not to conference presentations.
F) If a researcher submits a different abstract to each conference that publishes printed conference abstracts, there is no self-plagiarism.