This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology, Subject name: Microbiology
[{'content': 'Which of the following best describes lice? \nSelect and explain. \nA. They have wings, B. They cause tissue edema, C. They transmit epidemic typhus, relapsing fever, and trench fever, D. Pediculus humanus is the only species of louse', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pediculus humanus (head or body louse) and Phthirus pubis (crab louse) are wingless parasites exclusively affecting humans. Lice are important not only for the itching and discomfort they cause but also for the diseases they transmit. These disorders include epidemic typhus, relapsing fever, and trench fever. There is no evidence that lice secrete toxins.', 'role': 'assistant'}]