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 elastic modulus of dental amalgam: 
Select and explain. 
A. 21 GPa at slow rates of loading, B. 35 GPa at slow rates of loading, C. 94 GPa at high rates of loading, D. Both 1 and 3
A: 21 GPa at slow rates of loading
Answer: A: 21 GPa at slow rates of loading 
Explanation: Another example of strain-rate dependence is the elastic modulus of dental amalgam, which is 21 GPa at slow rates of loading and 62 GPa at high rates of loading. A viscoelastic material therefore may have widely different mechanical properties depending on the rate of load application, and for these materials, it is particularly important to specify the loading rate with the test results.
Ref:Craig’s Restorative Dentistry ed 14th pg 41