Your network consists of a single Active Directory domain. All network servers run Windows Server 2003 Service Pack 2 (SP2). You share a folder named Research. A user named User1 reports that he cannot access files in the Research share. You confirm that the Domain Users group is granted the Change permission for the Research share. You run the Cacls command as shown in the exhibit. (Click the Exhibit button.) You need to ensure that User1 can modify files in the Research share. You must prevent User1 from modifying permissions for the Research folder. To which group should you add User1? （）