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 success or failure of direct pulp capping depends on: 
Select and explain. 
A. Quality and amount of blood flow, B. History of previous pain, C. Age of the patient, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: The  direct  pulp  capping  procedure  has  been  known to be most  successful  in  younger  teeth  where  a  mechanical exposure is  a  dry sterile  field.