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: Pharmacology
In which of the following phases of clinical trials, healthy normal human volunteers participate: 
Select and explain. 
A. Phase–I, B. Phase–II, C. Phase–III, D. Phase–IV
A: Phase–I
Answer: A: Phase–I 
Explanation: None