Cómo estás

Hello, about the question: "Pedrito, how are you? " My answers were: ¿cómo estás?, ¿qué tal? and ¿cómo está?. The bot took my third choice as non correct. At the explanation tab however, it states : "even when we greet a person using their first name, we can still use a formal greeting as a sign of respect for an elderly person or because we feel that person prefers a more formal approach - in this instance we can still use the formal question: "¿Cómo está?", for example: Carmen, ¿cómo está?" So, I dont understand why cant we use the formal type for Pedrito too. I would think because he is a child but still a child could have the right to prefer a more formal approach. What is the case here, and why is the question: "Pedrito, ¿cómo está? wrong?