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
Radio activity was discovered by: 
Select and explain. 
A. Marie curie, B. Pierre curie, C. Rutherford, D. Henri bequerel
D: Henri bequerel
Answer: D: Henri bequerel 
Explanation: Ans. Henri bequerel