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?（）
- Ageneration Y ,raised on video, comprises 17 percent of the world population
- Bthe annual growth rate of the video-conferencing market is 23 percent
- Cthe U.S internet traffic annual growth rate is more than 40 percent
- Dthecisco long-term growth-rate target is 12 percent to 17 percent