Nurzhan was surprised because Maya had changed what Mr. Shanaman said to Papa to make the situation seem less serious than it was.
Mr. Shanaman explained that Nurzhan had gotten into a fight with Ossie, who had to get two stitches as a result, and that both boys were getting a two-day suspension. However, Maya translated Mr. Shanaman´s words to make it seem as if the other boy was to blame, and therefore Nurzhan´s punishment should not be as severe.
His father nods but clenches his fist which means he's not happy with the trial but he's trying. His mother also forces a smile. I think it's D because, though his parents may not like it, they are trying.