The best action to take in this scenario is to determine whether any additional effective arrangements are in place to verify individual access to secure areas, such as CCTV. This action is consistent with the audit principle of evidence-based approach, which requires the auditor to obtain sufficient and appropriate audit evidence to support the audit findings and conclusions1. By verifying the existence and effectiveness of other security controls, the auditor can assess the extent and impact of the nonconformity observed, and determine the appropriate audit finding and recommendation.
The other options are not the best actions to take in this scenario, because they are either premature or inappropriate. For example:
*Option A is inappropriate, because it is not the auditor's role to suggest specific solutions or improvements to the auditee, but rather to report the audit findings and recommendations based on the audit criteria and objectives2. A large sign in reception may not be an effective or feasible solution to address the issue of tailgating, and it may not reflect the root cause of the problem.
*Option C is premature, because it assumes that the control A.7.1 'security perimeters' is not adequately implemented, without verifying the existence and effectiveness of other security controls that may compensate for the observed nonconformity. The auditor should not jump to conclusions based on a single observation, but rather gather sufficient and appropriate audit evidence to support the audit finding3.
*Option D is premature, because it assumes that the control A.7.6 'working in secure areas' is not adequately implemented, without verifying the existence and effectiveness of other security controls that may compensate for the observed nonconformity. The auditor should not jump to conclusions based on a single observation, but rather gather sufficient and appropriate audit evidence to support the audit finding3.
*Option E is inappropriate, because it is not related to the observed nonconformity, which is about the access control to secure areas, not the information security requirements agreed upon with the supplier. The auditor should not raise a nonconformity based on irrelevant or incorrect audit criteria4.
*Option F is inappropriate, because it is not the auditor's role to suggest specific solutions or improvements to the auditee, but rather to report the audit findings and recommendations based on the audit criteria and objectives2. Requiring contractors to be accompanied at all times when accessing secure facilities may not be an effective or feasible solution to address the issue of tailgating, and it may not reflect the root cause of the problem.
References: 1: ISO 19011:2018, 5.2; 2: ISO 19011:2018, 6.6; 3: ISO 19011:2018, 6.2; 4: ISO 19011:2018,
6.3; : ISO 19011:2018; : ISO 19011:2018; : ISO 19011:2018; : ISO 19011:2018