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 group of thumb sucking in which the thumb do not contact the lower incisors, according to Subtleny et al: 
Select and explain. 
A. Group I, B. Group II, C. Group III, D. Group IV
C: Group III
Answer: C: Group III 
Explanation: Subtleny et al (1973) noted four types of thumb-sucking depending upon the

Amount of pushing of tongue inside the oral cavity
The contact between the thumb and the palate 
The contact between the thumb and anterior teeth.