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: Pharmacology
[{'content': 'A patient with cancer developed an extreme degree of radiation toxicity. Further history revealed that the dose adjustment of a particular drug was missed during the course of radiotherapy. Which of the following drugs required a dose adjustment during radiotherapy in order to prevent radiation toxicity \nSelect and explain. \nA. Vincristine, B. Dactinomycin, C. Cyclophosphamide, D. 6–Mercaptopurine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Anthracyclines and actinomycin-D (dactinomycin) can cause severe radiation toxicity. This is known as radiation recall syndrome.', 'role': 'assistant'}]