This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Amyotrophic Lateral Sclerosis and other motor neuron diseases, Subject name: Medicine
[{'content': "Upper motor neuron lesion is characterized by: \nSelect and explain. \nA. Weakness and spasticity, B. Fasciculation's, C. Rigidity, D. Localized muscle astrophy", 'role': 'user'}, {'content': "Answer: A \nExplanation: UMN LMN Pyramidal & Extra pyramidal tracts involved Motor neurone of spinal cord & Neurons of cranial nerve nuclei are involved Group of Muscle affected Single Muscle affected Tone - | Lost Power - Normal or no loss Lost Superficial & deep reflexes lost Lost Babinski's sign present Absent Clonus present Absent Clasp knife reflex present Absent Spasticity Absent", 'role': 'assistant'}]