Q. What was an important early drawback of the Clearboard system by Ishii et al. (1993).

• (A) it required people to move to a dedicated video conferencing facility at their workplace
• (B) as people moved closer to the board to talk with a remote colleague, the video system no longer picked them up
• (C) people found it uncomfortable to interact “looking down” at a colleague.
• (D) all of the above.