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: Microbiology
[{'content': 'Human immunodeficiency virus (HIV) affects: \nSelect and explain. \nA. Red blood cells, B. Fibroblasts, C. Helper T lymphocytes (CD4), D. Mast cells', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]