This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood, Subject name: Pathology
[{'content': 'Shape of birbeck granules is - \nSelect and explain. \nA. Tennis racket, B. Hockey stick, C. Bat, D. Ball', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Tennis racket o Under the electron microscope, Birbeck granules have a pentalaminar, rodlike, tubular appearance and some- times a dilated terminal end resembling tennis-racket appearance.", 'role': 'assistant'}]