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
Articulator based on Theory of an equilateral triangle is: 
Select and explain. 
A. Bonwill's theory articulator., B. Conical theory articulator., C. Spherical theory articulator., D. None
A: Bonwill's theory articulator.
Answer: A: Bonwill's theory articulator. 
Explanation: Bonwill's theory articulators 
• This articulator was designed by WGA Bonwill.
• According to the Bonwill's theory of occlusion, the teeth move in relation to each other as guided by the condylar and the incisal guidances.
• Bonwill's theory is also known as the Theory of equilateral triangle, according to which, the distance between the condyles is equal to the distance between the condyle and the midpoint of the mandibular incisors (incisal point).