The use of smart cards is the best solution in this scenario because they are physical tokens that an individual must possess in order to authenticate. Smart cards can store certificates and cryptographic keys and are frequently used in conjunction with a PIN, providing a two-factor authentication by combining something the user has (the card) with something the user knows (the PIN). Biometric authentication alone does not meet the stated need for 'something the user has,' as it typically falls under 'something the user is.' While security badges provide physical access control, they typically lack the cryptographic capabilities of smart cards and are therefore less secure for accessing IT resources. Password managers help manage something the user knows, but they do not provide the physical token aspect required.