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: Dental
TMJ has the following: 
Select and explain. 
A. 2 joint cavities & 1 articular disc., B. 1 joint cavity & 1 articular disc., C. 1 joint cavity & 2 articular disc., D. 2 joint cavities & 2 articular discs.
A: 2 joint cavities & 1 articular disc.
Answer: A: 2 joint cavities & 1 articular disc. 
Explanation: None