Section: Protection of Information Assets
Explanation:
Choices B, C and D are all possible problems that might occur, and would cause difficulties and financial
losses or waste of resources. However, if a new disaster recovery plan is not tested, the possibility of a
catastrophic service interruption is the most critical of all risks.

Explanation/Reference:
If proper identification and authentication are not performed during access control, no accountability can exist for any action performed.

Explanation/Reference:
Explanation:
The purpose of a mainframe audit is to provide assurance that processes are being implemented as required, the mainframe is operating as it should, security is strong, and that procedures in place are working and are updated as needed. The auditor may accordingly make recommendations for improvement.

Explanation/Reference:
Explanation:
Digital signatures provide integrity because the digital signature of a signed message (file, mail, document, etc.) changes every time a single bit of the document changes; thus, a signed document cannot be altered.
Depending on the mechanism chosen to implement a digital signature, the mechanism might be able to ensure data confidentiality or even timeliness, but this is not assured. Availability is not related to digital signatures.