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: Unknown
The first H2 receptor blocker was synthesized in 1972 by – 
Select and explain. 
A. Asch and Child, B. Sir James Black, C. Gaddum and Picarelli, D. Vane
B: Sir James Black
Answer: B: Sir James Black 
Explanation: Sir James Black. He synthesized the first H2 blocker burimamide; and subsequently cimetidine.
Asch and Child classified histamine receptors into H1 and H2.
Gaddum and Picarelli classified serotonin receptors into D type and M type.
Vane observed that aspirin acts by inhibiting PG synthesis.