This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'Which of the following show Regressive metamorphosis? (NOT RELATED) \nSelect and explain. \nA. Hydatid cyst, B. Cysticercoid, C. Cysticercus bovis, D. Cysticercus cellulosae', 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]