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
A gingival wall is difficult to obtain in primary molar
when it extends too far gingivally in class II cavities
because 
Select and explain. 
A. Facial pulp horn may be exposed, B. b)	Inclination of cervical enamel rods occlusally, C. Of marked cervical constriction, D. Prime contact is broad and flat
C: Of marked cervical constriction
Answer: C: Of marked cervical constriction 
Explanation: None