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
Histamine blocker in stomach act through : 
Select and explain. 
A. Decreasing cAMP in stomach, B. Increasing cAMP in stomach, C. Increasing IP3 in stomach, D. Decreasing IP3 in stomach
D: Decreasing IP3 in stomach
Answer: D: Decreasing IP3 in stomach 
Explanation: None