Telepresence and video conferencing have been an increasingly important component of the overall collaboration marker, which indicator is the best measure of the continued importance of these technologies going forward?（）
A.the annual growth rate of the video-conferencing market is 23 percent
B.generationY ,raised on video, comprises 17 percent of the world population
C.thecisco long-term growth-rate target is 12 percent to 17 percent
D.the U.S internet traffic annual growth rate is more than 40 percent
正确答案：参考A
