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
Dose of radiation during whole body exposure that leads to haematological syndrome is: 
Select and explain. 
A. 2 Gy, B. 10 Gy, C. 100 Gy, D. 200 Gy
A: 2 Gy
Answer: A: 2 Gy 
Explanation: A i.e. 2 Gy Total (whole) body irradiation dose > 1 to 2.5 Gy predominatly leads to hematopoietic syndromeQ; dose 5 to 8 Gy predominantly leads to gastrointestinal syndromeQ and doses 20 to 50Gy predominantly leads to cardiovascular syndromeQ.