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: Physiology
Normal adult person's blood contains: 
Select and explain. 
A. 40% neutrophils, B. 30% lymphocytes, C. 20% eosinophils, D. 10% basophils
B: 30% lymphocytes
Answer: B: 30% lymphocytes 
Explanation: None