This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological diagnosis and operative surgery, Subject name: Gynaecology & Obstetrics
[{'content': 'Goniometer is used for : \nSelect and explain. \nA. Amount of vaginal secretions, B. To measure width of genital hiatus, C. Gonococcal colony count, D. Urethrovesical Angle', 'role': 'user'}, {'content': "Answer: D \nExplanation: Goniometer It is used to measure baseline urethral angle and maximum strain angle of urethra with a cotton tip swab in place The bladder forms an angle of 100 degree with posterior urethral wall which is also responsible for maintaining urinary continence Ref: Berek and Novak's Gynecology; 15th edition; Chapter 27", 'role': 'assistant'}]