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
Mesial slope of distobuccal cusp of maxillary first
molar meets its distal slope at ______________ angle 
Select and explain. 
A. Acute angle, B. No specific angle, C. Obtuse angle, D. Right angle
D: Right angle
Answer: D: Right angle 
Explanation: None