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': 'Fibrinogen is present in which of the following granules of platelet? \nSelect and explain. \nA. a, B. b, C. g, D. d', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Platelets play a critical role in normal hemostasis. Their function depends on several glycoprotein receptors, a contractile cytoskeleton, and two types of cytoplasmic granules. a-Granules have the adhesion molecule P-selectin on their membranes and contain fibrinogen, fibronectin, factors V and VIII, platelet factor 4 (a heparin-binding chemokine), platelet-derived growth factor (PDGF), and transforming growth factor-b (TGF-b). Dense (or d) granules contain ADP and ATP, ionized calcium, histamine, serotonin, and epinephrine. Ref: Robbins 8th edition Chapter 4.', 'role': 'assistant'}]