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: Physiology
Secondary messengers include: 
Select and explain. 
A. cAMP, B. IP3, C. Diacylglycerol, D. All
D: All
Answer: D: All 
Explanation: A i.e. c-AMP; B i.e. IP3; C i.e. Diacylglycerol