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
Which of the following hardness test is a micro hardness test? 
Select and explain. 
A. Brinnel, B. Knoop, C. Shore-A, D. Rockwell
B: Knoop
Answer: B: Knoop 
Explanation: None