This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Gynaecology & Obstetrics
[{'content': 'A 55 year old woman diagnosed with ca cervix stage IIb is adviced for chemoradiation. Which of the following is true statement regarding radiation use ? \nSelect and explain. \nA. Dose/Intensity of radiation is inversely propoional to the square of distance of source, B. Rapidly proliferating cells are radioresistant, C. small blood vessels are radioresistant, D. small bowel is radioresistant', 'role': 'user'}, {'content': 'Answer: A \nExplanation: - Inverse square law:- Dose /Intensity of radiation is inversely propoional to the square of distance of source - Other options: If tissues with a rapid proliferation rate such as epithelium of the small intestine or oral cavity are irradiated, acute clinical symptoms develop within a few days to weeks The small bowel is paicularly vulnerable to acute early damage from radiation therapy Susceptibility of Selected Tissues to Radiation-Induced Cancer Susceptibility Tissues High Bone marrow, female breast, thyroid Moderate Bladder, colon, stomach, liver, ovary Low Bone, connective tissue, muscle, cervix, uterus, rectum', 'role': 'assistant'}]