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': 'Adenosine deaminase deficiency is seen in the following- \nSelect and explain. \nA. Common variable immunodeficiency., B. Chronic granulomatous disease, C. Nezelof syndrome, D. Severe combined immunodeficiency', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]