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
Which of the following best estimates the amount of radiation delivered to an organ in the radiation field: 
Select and explain. 
A. Absorbed dose, B. Equivalent dose, C. Effective dose, D. Exposure dose
A: Absorbed dose
Answer: A: Absorbed dose 
Explanation: A i.e. Absorbed dose Amount of radiation delivered to an organ is defined as absorbed doseQ. Whereas equivalent dose is a measure of biological damage caused by the absorbed dose depending on the relative effectiveness of type of radiation; and effective dose is a measure to assess the risk of carcinogenesis & genetic defect by calculating an imaginary total body dose depending on equivalent dose for each organ and relative sensitivity of each organ to radation.