The smart card, an intelligent token, is a credit card sized plastic card embedded with an integrated circuit chip. It provides not only memory capacity, but computational capability as well. The self-containment of smart card makes it resistant to attack as it does not need to depend upon potentially vulnerable external resources.
Because of this characteristic, smart cards are often used in different applications which require strong security protection and authentication. Option B is the most correct option, this is because Callback systems are not considered very reliable in the CISSP examination, Smart cards can also provide 2 mode authentication.
"Caller ID and callback options are great, but they are usually not practical because they require users to call in from a static phone number each time they access the network.
Most users are accessing the network remotely because they are on the road and moving from place to place." Pg. 428 Shon Harris: All-In-One CISSP Certification Guide.

Explanation/Reference:
Explanation:
2
The first and most important statement of ISC Code of Ethics Canon is to protect society, the common good, necessary public trust and confidence, and the infrastructure.
Incorrect Answers:
2
A: Act honorably, honestly, justly, responsibly, and legally is the second canon of the ISC Code of Ethics and less important that the first canon.
2
B: Advance and protect the profession is the fourth canon of the ISC Code of Ethics and less important that the first canon.
2
D: Provide diligent and competent service to principals is the third canon of the ISC Code of Ethics and less important that the first canon.
References:
https://www.isc2.org/ethics/default.aspx?terms=code of ethics

With mandatory access control (MAC), the authorization of a subject's access to an object is dependant upon labels, which indicate the subject's clearance.
Identity-based access control is a type of discretionary access control. A role-based access control is a type of non-discretionary access control.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the
Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 33).