This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Human identification, Subject name: Forensic Medicine
[{'content': 'Which of the following is used for biometric evaluation? \nSelect and explain. \nA. Iris, B. Pupil, C. Lens, D. Cornea', 'role': 'user'}, {'content': "Answer: A \nExplanation: * Each person's Iris has a unique pattern which is not changed from bih until death. The pattern is different even in identical twins. * Retinal scan is performed by casting an undetectable ray of low energy infrared light into a person's eye as he looks through scanner's eye piece, which outlines a circular path on the retina. The results of the scan is conveed to computer code & stored in database. * Retina patterns may be altered in cataracts, glaucoma, retinal degeneration & diabetes.", 'role': 'assistant'}]