<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:An 82-year-old woman is brought to the emergency department after losing consciousness at her nursing home. She had been watching TV for several hours and while getting up to use the bathroom, she fell and was unconscious for several seconds. She felt dizzy shortly before the fall. She does not have a headache or any other pain. She has a history of hypertension, intermittent atrial fibrillation, and stable angina pectoris. Current medications include warfarin, aspirin, hydrochlorothiazide, and a nitroglycerin spray as needed. Her temperature is 36.7C 98.1F, pulse is 100min and regular, and blood pressure is 10256 mm Hg. Physical exam shows a dry tongue. A fold of skin that is pinched on the back of her hand unfolds after 2 seconds. Cardiopulmonary examination shows no abnormalities. Further evaluation of this patient is most likely to show which of the following findings?? A: Elevated serum concentration of cardiac enzymes, B: Absent P waves on ECG, C: Elevated blood urea nitrogen concentration, D: Hypodense lesions on CT scan of the head, E: Elevated serum creatine kinase concentration,  <response>: This is a clinical vignette about an elderly woman with a history of hypertension, atrial fibrillation, and angina who lost consciousness after getting up from watching TV. The stem provides details about her vital signs, physical exam findings, and medical history. The key findings in the stem are the transient loss of consciousness, history of atrial fibrillation, dry tongue, and delayed capillary refill. These suggest she may be volume depleted or have an arrhythmia as the cause of her syncope. Choice A can be eliminated because there is no evidence she had a cardiac event. Choice B is plausible because atrial fibrillation could have caused the syncope.Choice C is plausible because her volume status may be low leading to elevated BUN. Choice D is unrelated to the presentation.Choice E is incorrect because there is no evidence of muscle injury.C: Elevated blood urea nitrogen concentration 