Explanation: Trusted computing base (TCB) refers to hardware, software, controls, and processes that cause a computer system or network to be devoid of malicious software or hardware. Maintaining the trusted computing base (TCB) is essential for security policy to be implemented successfully. Answer: D is incorrect. Internet Protocol Security (IPSec) is a standard-based protocol that provides the highest level of VPN security. IPSec can encrypt virtually everything above the networking layer. It is used for VPN connections that use the L2TP protocol. It secures both data and password. IPSec cannot be used with Point-to-Point Tunneling Protocol (PPTP). Answer: A is incorrect. The Common data security architecture (CDSA) is a set of layered security services and cryptographic framework. It deals with the communications and data security problems in the emerging Internet and intranet application space. It presents an infrastructure for building cross-platform, interoperable, security-enabled applications for client-server environments. Answer: B is incorrect. An application programming interface (API) is an interface implemented by a software program which enables it to interact with other software. It facilitates interaction between different software programs similar to the way the user interface facilitates interaction between humans and computers. An API is implemented by applications, libraries, and operating systems to determine their vocabularies and calling conventions, and is used to access their services. It may include specifications for routines, data structures, object classes, and protocols used to communicate between the consumer and the implementer of the API.