Analysis: Article 75 of the Criminal Procedure Law stipulates: "If the people's courts, people's procuratorates and public security organs take compulsory measures beyond the statutory time limit, the criminal suspect, the defendant and his legal representative, close relatives or lawyers entrusted by the criminal suspect and the defendant have the right to demand the cancellation of compulsory measures." Therefore, in item A, A has the right to demand the cancellation of compulsory measures when he is detained for an extended period. Article 28 stipulates that for judges, prosecutors and investigators, the parties and their legal representatives have the right to ask them to withdraw, and lawyers or defenders have no right to ask questions, so item B is incorrect. Paragraph 2 of Article 37 stipulates that, with the permission of the People's Procuratorate or the People's Court, a defense lawyer may collect materials related to the case from the victim or his close relatives or witnesses provided by the victim. B is a non-lawyer defender and does not have this right, so item D is wrong. It is the proper meaning of being a defender to state defense opinions to the procuratorate in item C. According to Article 25 1 of the Criminal Procedure Rules of the People's Procuratorate, "When examining a case, the People's Procuratorate shall interrogate the criminal suspect and listen to the opinions of the victim, the criminal suspect and the person entrusted by the victim". Therefore, item C is correct, and this question should choose AC.