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: Pathology
Minimum dose of tetracycline which causes discoloration of teeth: 
Select and explain. 
A. 10mg/kg Body weight., B. 20mg/kg Body weight., C. 30mg/kg Body weight., D. 40mg/kg Body weight.
B: 20mg/kg Body weight.
Answer: B: 20mg/kg Body weight. 
Explanation: None