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: Biochemistry
[{'content': 'Synthesis of an immunoglobulin in membrane bound of secretory form is determined by - \nSelect and explain. \nA. One turn to two turn joining rule, B. Class switching, C. Differential RNA processing, D. Allelic exclusion', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]