Article 37 of the Criminal Procedure Law stipulates that defense lawyers can meet and correspond with criminal suspects and defendants in custody. Other defenders, with the permission of the people's courts and people's procuratorates, may also meet and correspond with criminal suspects and defendants in custody. If a defense lawyer holds a lawyer's practice certificate, a law firm's certificate, a power of attorney or a letter of legal aid to ask for a meeting with the criminal suspect or defendant in custody, the detention center shall arrange the meeting in time, and it shall not exceed 48 hours at the latest. In cases of endangering national security, terrorist activities and especially serious bribery crimes, defense lawyers should obtain permission from the investigation organ when meeting with the criminal suspect in custody during the investigation. The investigation organ shall notify the detention center of the above situation in advance. When a defense lawyer meets a criminal suspect or defendant in custody, he can understand the case and provide legal advice. From the date when the case is transferred for examination and prosecution, the relevant evidence may be verified with the criminal suspect or defendant. Defense lawyers are not monitored when meeting with criminal suspects and defendants. The provisions in paragraphs 1, 3 and 4 are applicable to the meetings and correspondence between defense lawyers and the criminal suspects and defendants under supervision. Therefore, in "verifying relevant evidence", option A is correct and option B is wrong. Relevant evidence can only be verified from the date when the case is transferred for review and prosecution. Article 46 of the Criminal Procedure Law stipulates that defense lawyers have the right to keep confidential the relevant information and information of their clients they know in their practice. However, if a defense lawyer knows that the client or other people are preparing or committing crimes that endanger national security, public security and seriously endanger the personal safety of others in his practice activities, he shall promptly inform the judicial organs. Therefore, in option C, Li is committing a criminal act endangering national security, and Lin should inform the judicial organ in time, instead of keeping a secret, so option C is wrong. Article 39 of the Criminal Procedure Law stipulates that in the process of investigation, examination and prosecution, defenders have the right to apply to the people's procuratorate and the people's court for retrieval if they believe that the evidence materials collected by the public security organs and the people's procuratorate to prove the innocence or light crime of the criminal suspect or defendant have not been submitted. Article 47 stipulates that defenders and agents ad litem have the right to appeal or accuse the public security organs, people's procuratorates, people's courts and their staff members of obstructing them from exercising their litigation rights according to law. The people's procuratorate shall promptly examine the complaint or accusation, and if the situation is true, notify the relevant authorities to correct it. Therefore, Lin has the right to apply for evidence to prove that the suspect is innocent or guilty. If he thinks that the judicial organs hinder him from exercising his litigation rights, he has the right to appeal or accuse to the people's procuratorate instead of the "people's court", then D is wrong.