What is the ruling on free mixing of men and women in classroom rows?

Question:
May Allah reward you with good. This is a letter we received from a sister, A.M.M., from Iraq. In her letter, she says that she is a religious girl in a righteous family, but the problem is that she is studying in the first year of university, and the university is mixed with boys and girls. She asks about the ruling on her mixing with the young men. She says that she tried to leave the university, but her father refused and got angry, saying, "If you leave the university, I will divorce your mother," or she says he swore that he would divorce her mother if she left the university. He said that more than three times. So, is it permissible for me to disobey my father and leave the university? And does the divorce take effect on my mother?

Answer:
As for studying in a mixed university, it is a trial and a great danger. You are not allowed to study in a mixed university because this is a danger to your religion, your morals, and your honor. So, you must refrain from studying in a mixed university and preserve your land and your religion, even if your father gets angry. This is because the Messenger (peace be upon him) said, "Obedience is only in what is right; there is no obedience to a created being in sin." And your father, if he has jealousy, should fear Allah and prevent you from the university; he should not allow you to go to the university, but prevent you. Likewise, it is obligatory for the jealous father and the jealous mother to do so. For your mixing with the young men involves a great danger, and you are not allowed to mix with them. You may stay at home, and the knowledge you have obtained is sufficient. You have no obedience to your father in this matter, just as if he ordered you to drink intoxicants or commit unlawful sexual intercourse; you have no obedience to him in that. Likewise, if he ordered you to go out as a disbeliever, or uncovered, or with your head exposed, or the like, all of this is wrong, and you have no obedience to him. Rather, obedience is in what is right, as the Chosen One (peace and blessings be upon him) said. Allah commanded His Prophet, and there is no disobedience to you in what is right. So, Allah (peace and blessings be upon him) does not order us in what is right (peace and blessings be upon him), but for teaching and clarification. The evil of mixing is great, and its consequence is severe. So, fear Allah and advise your father and your mother to fear Allah (Exalted and Majestic is He) and to prevent you from this. If he divorces your mother, it will not be a loss for you; perhaps Allah will make it a good thing for you, better than him. Obedience to the parent in sin is a matter that is not permissible. And his threatening with divorce does not obligate you to study in a mixed university, even if he divorces your mother. So, we ask Allah for guidance for everyone.