Regarding the situation of resigning your job and the implications for your mobile phone under RDM, the correct action to take is:
D. Call IT Services for support, and they will assist.
This option is appropriate as it aligns with the procedure outlined in Document 2: when an employee leaves REV, IT Services will sever access to REV information assets and remove any REV data stored on the mobile device. It's important to contact IT Services to ensure all necessary steps are followed correctly.