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
Which of the following is true about thermal and electrical pulp tests after trauma? 
Select and explain. 
A. Sensitivity tests evaluate the nerve and circulatory condition of the tooth, B. False positive tests are more likely than false negative tests, C. It may take up to nine months for normal blood flow to return., D. It may take a few hours for normal blood flow to return
C: It may take up to nine months for normal blood flow to return.
Answer: C: It may take up to nine months for normal blood flow to return. 
Explanation: None