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: Gynaecology & Obstetrics
[{'content': "Kamla, a 30-yr-old lady examined for infertility by hysterosalpingography, reveals 'Bead - like' fallopian tube and clubbing of ampulla. The most likely cause is: \nSelect and explain. \nA. Gonococcus, B. Mycoplasma, C. Chlamydia, D. Mycobacterium tuberculosis", 'role': 'user'}, {'content': 'Answer: D \nExplanation: The following findings on hysterosalpingogram strongly suggest tubercular salpingitis:\n• A rigid nonperistaltic pipe like tube, called lead pipe appearance\n• Beading and variation in filling density\n• Calcification of the tube\n• Cornual block\n• A jagged fluffiness of the tubal outline\n• Vascular or lymphatic intravasation of the dye\n• Tobacco-pouch appearance seen on naked eye examination.\nAlso Note:\n• In a proven case of genital tuberculosis, hysterosalpingography is contraindicated as it may spread the infection.\n• In TB Endometritis on HSG: The uterine cavity is shrivelled and obliterated by adhesions giving honeycomb appearance.\n• On USG: Incomplete septation of the tubal wall “Cogwheel sign” is a marker for acute disease. Thin wall and beaded string appearance is a marker for chronic disease.', 'role': 'assistant'}]