question: Q:A 53-year-old woman comes to the physician because of a 3-year history of increasing weakness of her extremities and neck pain that is worse on coughing or sneezing. She first noticed weakness of her right upper extremity 3 years ago, which progressed to her right lower extremity 2 years ago, her left lower extremity 1 year ago, and her left upper extremity 6 months ago. She has had difficulty swallowing and speaking for the past 5 months. Vital signs are within normal limits. Examination shows an ataxic gait. Speech is dysarthritic. Muscular examination shows spasticity and muscle strength is decreased in all extremities. There is bilateral atrophy of the sternocleidomastoid and trapezius muscles. Deep tendon reflexes are 4+ bilaterally. Plantar response shows an extensor response bilaterally. Sensation is decreased below the C5 dermatome bilaterally. Which of the following is the most likely cause of this patient's symptoms?? 
  {'A': 'Foramen magnum meningioma', 'B': 'Cerebellar astrocytoma', 'C': 'Amyotrophic lateral sclerosis', 'D': 'Multiple sclerosis', 'E': 'Cerebral glioblastoma multiforme\n"'},