You are answering a USMLE-style medical question. Question: A 24-year-old female presents to the emergency department with a chief complaint of an inability to urinate. She states that this has been one of many symptoms she has experienced lately. At times she has had trouble speaking and has noticed changes in her vision however these episodes occurred over a month ago and have resolved since then. Two days ago she experienced extreme pain in her face that was exacerbated with brushing her teeth and plucking out facial hairs. The patient has no relevant past medical history, however, the patient admits to being sexually abused by her boyfriend for the past year. Her current medications include ibuprofen for menstrual cramps. On physical exam it is noted that leftward gaze results in only the ipsilateral eye gazing leftward. The patient's initial workup is started in the emergency department. Her vital signs are within normal limits and you note a pale and frightened young lady awaiting further care. Which of the following is the best initial test for this patient's chief complaint? Options: A) Head CT B) Head MRI C) Lumbar puncture D) Domestic abuse screening and exploring patient's life stressors Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.