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
[{'content': 'Serotonin, a mediator of inflammation in our body, is secreted /released by: \nSelect and explain. \nA. Leukocytes, B. Endothelial cell, C. Mast cell, D. Platelet', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer- D. PlateletSerotonin :It is found in the intestinal mucosa, brain tissue & platelets.Release of serotonin (and histamine) from platelets is stimulated when platelets aggregate after contact with collagen, thrombin, adenosine diphosphate (ADP), and antigen-antibody complexes.', 'role': 'assistant'}]