Accreditation is the authorization by management to implement software or systems in a production environment. This authorization may be either provisional or full.
The following are incorrect answers:
Certification is incorrect. Certification is the process of evaluating the security stance of the software or system against a selected set of standards or policies. Certification is the technical evaluation of a product. This may precede accreditation but is not a required precursor.
Acceptance is incorrect. This term is sometimes used as the recognition that a piece of software or system has met a set of functional or service level criteria (the new payroll system has passed its acceptance test). Certification is the better tem in this context.
Evaluation is incorrect. Evaluation is certainly a part of the certification process but it is not the best answer to the question.
Reference(s) used for this question:
The Official Study Guide to the CBK from ISC2, pages 559-560
AIO3, pp. 314 - 317
AIOv4 Security Architecture and Design (pages 369 - 372)
AIOv5 Security Architecture and Design (pages 370 - 372)

Section: Security Assessment and Testing

References: RFC 2459 : Internet X.509 Public Key Infrastructure Certificate and CRL Profile; GUTMANN, P., X.509 style guide.

Rootkits are software that is designed to get, keep and provide access to attackers by hooking into key components of the operating system like the kernel or system drivers. Rootkits commonly try to hide their presence by affecting operating system functionality and can subvert detection software like Antivirus Scanners.
Removing a rootkit may be impossible because the software can irrevocably change components of the operating system. The OS may need to be completely reinstalled to remove the infestation.
At any rate, a computer infected with ANY malware should never be trusted again and infestation should be mitigated by a completely new install of the OS from trusted media.
The following answers are incorrect:
-User-Mode Rootkit: This isn't correct because User-mode rootkits don't include device drivers.
-Malware: This isn't a bad answer but it isn't as specific as the correct answer. Malware is a very broad term that describes any software that is written to do something nefarious.
-Kernel-mode Badware: This isn't really a computer term. But it should be.
The following reference(s) was used to create this question: 2013. Official Security+ Curriculum.