The correct answer is: Option C. That children are sent to school to learn, not to teach, so the students in this case were in the wrong by trying to "teach" others something by wearing armbands.
The text argues the fact that children are able to teach elders by remarking their lack of experience to do so, but it mainly makes emphasis in their "need to learn, not teach." Therefore, it is settled that children should not be allowed to teach while they are still in their learning phase.