This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nerve Injuries - 1, Subject name: Orthopaedics
[{'content': "All are true regarding brachial plexus injury, except: \nSelect and explain. \nA. Preganglionic lesions have a better prognosis than postganglionic lesions, B. Erb's palsy causes paralysis of the abductors and external rotators of the shoulder, C. In Klumpke's palsy, Horner's syndrome may be present on the ipsilateral side, D. Histamine test is useful to differentiate between the preganglionic and postganglionic lesions", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Preganglionic lesions have a poor prognosis as these do not recover and are surgically irreparable. Postganglionic lesions have better prognosis than preganglionic lesions and histamine test is useful in making the distinction', 'role': 'assistant'}]