This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
The indication for the use of Kloehn type cervical head gear is in: 
Select and explain. 
A. Maxillary retrusion, B. Maxillary protrusion, C. Mandibular prognathism, D. Mandibular retrognathism
B: Maxillary protrusion
Answer: B: Maxillary protrusion 
Explanation: None