The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 68-year-old man comes to the physician with a 1-week history of painless hematuria. A CT scan of the urinary tract shows areas of bladder wall thickening. Cystoscopy shows several sessile masses with central necrosis arising from the bladder wall. A biopsy specimen of the bladder masses shows moderately differentiated urothelial cells with abundant mitotic figures and nuclear atypia. The patient most likely has a history of exposure to which of the following?   (A) Ionizing radiation   (B) Aromatic amines   (C) Aflatoxins   (D) Radon
['(B) Aromatic amines <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Ionizing radiation \n (B) Aromatic amines \n (C) Aflatoxins \n (D) Radon <> possible answers', '  A 68-year-old man comes to the physician with a 1-week history of painless hematuria. A CT scan of the urinary tract shows areas of bladder wall thickening. Cystoscopy shows several sessile masses with central necrosis arising from the bladder wall. A biopsy specimen of the bladder masses shows moderately differentiated urothelial cells with abundant mitotic figures and nuclear atypia. The patient most likely has a history of exposure to which of the following? <> context@']