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
HOME should be carried out for: 
Select and explain. 
A. 1 minute., B. 20-30 sec., C. 10 sec., D. 15-20 sec.
B: 20-30 sec.
Answer: B: 20-30 sec. 
Explanation: None