Q. A 70-year-old male presents to his physician’s office with a complaint of urinary incontinence. He reports that he often feels a sudden, urgent need to urinate, and sometimes leaks urine before he can get to the toilet. These episodes have been occurring more frequently over the past year, and are disrupting his sleep and daily activities. The patient has a history of prostate cancer, and has been taking medications to manage his symptoms. Physical examination reveals an enlarged prostate, but no other abnormalities. Which of the following is the most likely cause of this incontinence?