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': 'Most common type of class II mutation in cystic fibrosis is \nSelect and explain. \nA. Missense mutation, B. Frameshift, C. Non sense, D. Deletion', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D. DeletionClass II mutation : 'Deletion' of phenylalanine amino acid so CFTR protein fails to reach cell membrane", 'role': 'assistant'}]