This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal System, Subject name: Physiology
[{'content': 'Liver synthesises all except \nSelect and explain. \nA. C3 complement component, B. Haptoglobin, C. Fibrinogen, D. Immunoglobulin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Immunoglobulins are synthesized by the B-lymphocytes.', 'role': 'assistant'}]