The primary security concern associated with the implementation of smart cards is that the cards can be misplaced, lost, stolen, or damaged, resulting in the compromise of the user’s identity, credentials, or data stored on the card. The other options are not the primary security concern, but rather secondary or minor issues. The cards have limited memory, which may affect the performance or functionality of the card, but not the security. Vendor application compatibility may affect the interoperability or usability of the card, but not the security. Mobile code can be embedded in the card, which may introduce malicious or unauthorized functionality, but this is a rare and sophisticated attack that requires physical access to the card and specialized equipment. References: CISSP All-in-One Exam Guide, Eighth Edition, Chapter 5, p. 275; Official (ISC)2 CISSP CBK Reference, Fifth Edition, Chapter 6, p. 348.