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 main form of iron carbide found in 18-8 steel: 
Select and explain. 
A. Martensite, B. Ferrite, C. Austenite, D. Pearlite
C: Austenite
Answer: C: Austenite 
Explanation: None