Is it considered disbelief if I answer on an exam that prohibiting polygyny is a manifestation of justice or equality between the sexes, knowing that I may not be convinced by the answer or be unaware of its contradiction with religion? And do I remain a disbeliever until I inform my friend, to whom I conveyed the answer, that what I said was wrong?

It is not permissible to study materials that contradict the Sharia unless there is a necessity or a recognized benefit, such as clarifying their errors, provided one is capable of distinguishing truth from falsehood. It is permissible to answer in exams based on what was studied, as long as the consequence is failure and it does not lead to the propagation of evil. It is not permissible to inform colleagues of answers that contradict the Sharia, as this constitutes deception and aiding in the spread of falsehood, and this is forbidden. This does not amount to disbelief unless one believes in it or is excused due to ignorance or misinterpretation. It is obligatory to advise a friend and teach him the truth if he cannot distinguish it.