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
All are true about Experimental trials except: 
Select and explain. 
A. Can’t double blind in animal trials, B. All animal trials are unethical, C. Can’t do interim analysis, D. Are always prospective
A: Can’t double blind in animal trials
Answer: A: Can’t double blind in animal trials 
Explanation: None