Which group member is showing effective nonverbal communication in a group discussion?

A. Jack realizes that no one else in his group would make a good leader, so he decides he should take this role.
B. Jamal sees that Mariah looks nervous as she speaks, so he gives her a reassuring nod.
C. As Madison talks, she keeps her eyes on Leena because so far no one but Leena has bothered to say anything.
D. Akram thinks Nick has been talking too much, so he cuts him off to give other people in the group a chance to speak.​