This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Demography and family planning, Subject name: Social & Preventive Medicine
[{'content': '"Persona" is a method of - \nSelect and explain. \nA. Natural contraceptive, B. Hormonal contraceptive, C. Barrier contraceptive, D. IUCD', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Persona It is a microcomputer attached to a micro-labaratory. It measures the level if oestrone-3-glucuronide and LH in the morning urine by dipping a test stick in the urine. Green light shows contraception unlikely Red light shows feile period and warns the probable ovulation and contraception. The failure rate with this technique is approximately 6 per 100 per women Ref : Shaw textbook of gynecology Pgno : 266', 'role': 'assistant'}]