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: ENT
Normal volume of middle ear and mastoid ? 
Select and explain. 
A. 1 cc, B. 6 cc, C. 12 cc, D. 15 cc
B: 6 cc
Answer: B: 6 cc 
Explanation: Ans. is 'b' i.e., 6 cc l ReJ: Glasscock-shambaugh surgery of the ear p. 65)The normal average volume of middle ear and mastoid is 6 cc.