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: Radiology
What does this symbol signify? 
Select and explain. 
A. Radiation hazard, B. Recyclable material biohazard, C. Waste, D. Fan at high speed
A: Radiation hazard
Answer: A: Radiation hazard 
Explanation: This symbol is used to depict radiation in the area.