Not the student but the teacher
So, the teacher, let's call him Mr. A, had a reputation for being a phenomenal teacher who had every student engaged/invested in his class, no matter how mundane the subject. Any time he asked a question, every student's hand would shoot in the air with them shouting things like "call on me!" or "I know the answer!"
Simply, Mr. A developed a reputation in the district as one of its best teachers.
Fast forward a couple years and I'm grabbing coffee with Mr. A and I ask him "what's your trick? How did you get every student bought in?"
His response, "well, I told the kids every time we had a visitor in class, I need you all to raise your hand like I was giving away free candy. BUT if you don't know the answer raise your left hand. If you do know it, raise your right hand, so I know who to call on and we all look good. Worked like a charm."