This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'In which case homologous artificial insemination is used in females: \nSelect and explain. \nA. Hormonal disturbance, B. Tubal block, C. Cervical factor, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cervical factor: cervical mucous protects sperm from the hostile environment of the vagina and also phagocytosis.\ncervical factor when cannot be treated is overcome by ART procedures IUI, IVF, GIFT.\ncervical mucus quality improved by conjugated estrogen 1.25mg orally daily starting on day 8 for 5 days', 'role': 'assistant'}]