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: Pathology
Which one of the following acts to increase the release of Ca" from endoplasmic reticulum? 
Select and explain. 
A. Inositol triphosphate, B. Parathyroid hormone, C. 1, 25-dihydroxy cholecalciferol, D. Diacylglycerol
A: Inositol triphosphate
Answer: A: Inositol triphosphate 
Explanation: Ans. is 'a' i.e., Inositol triphosphateo Inositol triphosphate (IP3) mobilises ca + from endoplasmic reticulum.o Diacylglycerol (DAG) enhances activation of protein kinase C by ca".