What type of authentication does the dod require to access sensitive data on mobile devices and/or e-mail?

Actually dod requires a digital type of authentication and a secure password inorder to access sensitive data on mobile devices and email, which may in the form of two step authentication code, then in the form digital phone calls, and then in the form of alphanumeric passwords and finally in the form of finger prints authentications or face recognition verification..

The answer for your specific question is d.