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: Ophthalmology
The most toxic intraocular foreign body is a paicle of: 
Select and explain. 
A. Copper, B. Iron, C. Tantalum, D. Aluminium
A: Copper
Answer: A: Copper 
Explanation: Ans. Copper