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
The thixotropic theory claims that: 
Select and explain. 
A. The principle fibres of the periodontal ligament has the major responsibility in supporting the tooth and transmitting forces to the bone, B. The periodontal ligament has the rheologic behaviour of a thixotropic gel., C. The displacement of the tooth is largely controlled by fluid movements., D. None of the above
B: The periodontal ligament has the rheologic behaviour of a thixotropic gel.
Answer: B: The periodontal ligament has the rheologic behaviour of a thixotropic gel. 
Explanation: None