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
Investment breakdown or air bubbles on wax can affect the casting, as: 
Select and explain. 
A. Leads to the surface roughness of casting., B. Fins on casting., C. Distorted casting., D. Microporosity.
A: Leads to the surface roughness of casting.
Answer: A: Leads to the surface roughness of casting. 
Explanation: None