Adam is the moderator of a group discussion, and one speaker in his group has been talking for a very long time. He can tell that the others in the group are getting impatient.What is the best approach Adam can take as moderator?A. He should listen closely, and wait patiently to share a fact or opinion.B. He should raise his voice and demand that the speaker remain quiet.C. He should interrupt the speaker to pose a new question to the group.D. He should let the speaker finish, and then remind the group of the ground rules.