Which aspect of penetration testing do screenshots best provide evidence for?

Screenshots serve as powerful evidence for successful exploits and access gained during penetration testing. They visually document the outcomes of tests, such as administrators gaining unauthorized access to systems or data. This visual proof demonstrates not only that a vulnerability was exploited but also illustrates the extent of the access achieved, which is crucial for validating the effectiveness of the penetration test.

In contrast, other options focus on aspects that are less conducive to visual representation through screenshots. For instance, network traffic analysis typically requires tools and logs rather than images, user credential management involves procedural aspects that may not be effectively illustrated visually, and firewall effectiveness is usually assessed through logging and result analysis rather than screenshots showing specific exploits. Therefore, screenshots most clearly represent instances of successful exploitation and the related access gained.