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
What is the value of poisons ratio for ideal isotropic material: 
Select and explain. 
A. 0.3, B. 0.4, C. 0.5, D. 0.6
C: 0.5
Answer: C: 0.5 
Explanation: For most engineering materials poisons ratio is 0.3