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
Shape of birbeck granules is - 
Select and explain. 
A. Tennis racket, B. Hockey stick, C. Bat, D. Ball
A: Tennis racket
Answer: A: Tennis racket 
Explanation: 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.