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
Structural classification of B-lactamases was given by: 
Select and explain. 
A. Amber, B. Bush, C. Ross, D. Kennedy
A: Amber
Answer: A: Amber 
Explanation: Amber gave molecular / structural classification, where B-lactamases are classified into 4 categories (A,B,C,D)
Bush gave funtional classification of B-lactamases.