Threat and vulnerability assessments are important PRIMARILY because they are the basis for setting control objectives. Control objectives are the desired outcomes or goals of implementing security controls in an information system. They are derived from the risk assessment process, which identifies and evaluates the threats and vulnerabilities that could affect the system's confidentiality, integrity and availability. By conducting threat and vulnerability assessments, an organization can determine the level of risk it faces and establish the appropriate control objectives to mitigate those risks.

The document that should include contact information for representatives of equipment and software vendors is the business continuity plan (BCP) because it provides the guidance and procedures for restoring the organization's critical business functions and operations in the event of a disruption or disaster, and may require contacting external parties such as vendors for assistance or support. Information security program charter is not a good document for this purpose because it does not provide any guidance or procedures for business continuity or disaster recovery. Business impact analysis (BIA) is not a good document for this purpose because it does not provide any guidance or procedures for business continuity or disaster recovery. Service level agreements (SLAs) are not good documents for this purpose because they do not provide any guidance or procedures for business continuity or disaster recovery. Reference: https://www.isaca.org/resources/isaca-journal/issues/2017/volume-2/business-continuity-management-lifecycle https://www.isaca.org/resources/isaca-journal/issues/2016/volume-4/business-impact-analysis