This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'The interaction of histamine with its H2 receptor in the parietal cell results in \nSelect and explain. \nA. An increase in intracellular sodium concentration, B. An increase in intracellular cAMP production, C. An increase in intracellular cGMP production, D. A decrease in intracellular calcium concentration', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]