<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 67-year-old woman comes to the emergency department 1 hour after her husband saw her faint shortly after getting out of bed from a nap. She regained consciousness within 30 seconds and was fully alert and oriented. She has had 2 similar episodes in the last 5 years, once while standing in line at the grocery store and once when getting out of bed in the morning. 24-hour Holter monitoring and echocardiography were unremarkable at her last hospitalization 1 year ago. She has hypertension, depression, and asthma. Current medications include verapamil, nortriptyline, and an albuterol inhaler as needed. Her temperature is 37C 98.4F, pulse is 74min and regular, respirations are 14min, blood pressure is 11472 mm Hg when supine and 9560 mm Hg while standing. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. A complete blood count and serum concentrations of electrolytes, urea nitrogen, creatinine, and glucose are within the reference range. Bedside cardiac monitoring shows rare premature ventricular contractions and T-wave inversions in lead III. Which of the following is the most likely cause of this patients symptoms?? A: Adrenal insufficiency, B: Autonomic dysfunction, C: Structural cardiac abnormality, D: Hemorrhagic blood loss, E: Cardiac arrhythmia,  <response>: This is a clinical case about a 67-year-old woman with a history of recurrent syncope. The key findings in the history are:- 3 episodes of syncope in the past 5 years, occurring when getting out of bed or standing up, and resolving quickly- Past workup including Holter monitor and echocardiogram were unremarkable- Medical history of hypertension, depression, and asthma- Currently on verapamil, nortriptyline, and albuterol - Vital signs show orthostatic hypotension - Physical exam is unremarkable except for T-wave inversions on cardiac monitoringBased on the history of syncope only when changing positions along with orthostatic hypotension on exam, this points to autonomic dysfunction as the likely cause. The other choices can be ruled out based on the unremarkable past workup and lack of supportive history or exam findings.B: Autonomic dysfunction 