A skills inventory would help identify- the available resources, any gaps and the training requirements for developing resources. Proficiency testing is useful but only with regard to specific technical skills. Job descriptions would not be as useful since they may be out of date or not sufficiently detailed. An organization chart would not provide the details necessary to determine the resources required for this activity.

Explanation
Choice A represents the primary driver for the information security manager to make use of external resources.
The information security manager will continue to be responsible for meeting the security program requirements despite using the services of external resources. The external resources should never completely replace the role of internal resources from a strategic perspective. The external resources cannot have a better knowledge of the business of the information security manager's organization than do the internal resources.

Explanation
A Trojan is a program that gives the attacker full control over the infected computer, thus allowing the attacker to hijack, copy or alter information after authentication by the user. IP spoofing will not work because IP is not used as an authentication mechanism. Man-in-the-middle attacks are not possible if using SSL with client-side certificates. Repudiation is unlikely because client-side certificates authenticate the user.