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
The medical speciality in which there is statistically
higher incidence of leukemia: 
Select and explain. 
A. Dentistry, B. Internal medicine, C. Radiology, D. Anesthesiology
C: Radiology
Answer: C: Radiology 
Explanation: Radiation causes cancer by modifying DNA. The most likely mechanism is a multistep process including accumulation of radiation-induced gene mutation. These mutations are usually base substitutions, insertions and deletions of bases, rearrangements caused by breakage and abnormal rejoining of DNA strands, or changes in the copy number of DNA segments. When the mutations involve growth-regulating genes—activation of oncogenes or inactivation of tumor suppressor genes—they can deregulate cell growth or differentiation or both and ultimately lead to neoplastic development. In principle, even one radiation photon may initiate cancer formation.