This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology in Relation to Reproduction, Subject name: Gynaecology & Obstetrics
[{'content': 'Which hormone is not affected by menstrual cycle - \nSelect and explain. \nA. Estrogen, B. Progesterone, C. Gonadotropins, D. Prolactin', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Prolactin o Prolactin levels do not fluctuate much during the menstrual cycle.", 'role': 'assistant'}]