Which testing technique is commonly suited for identifying risks in highly dynamic environments?

Error Guessing is particularly suited for identifying risks in highly dynamic environments due to its exploratory nature. This technique relies on the tester's experience and intuition to anticipate where defects may occur. In environments that change frequently—such as those that involve agile development or rapidly evolving applications—traditional scripted testing may not be as effective because it can miss new issues that arise from modifications or new features.

By employing Error Guessing, testers can focus on likely failure points based on past experiences, knowledge of similar systems, and an understanding of the current application's complexities. This approach allows for a more flexible and adaptive testing strategy, which is crucial in environments that are subject to swift changes.

In contrast, other techniques like Regression Testing are more structured and aimed at verifying that changes haven’t adversely affected existing functionality, but they may not proactively identify new risks. Performance Testing focuses on how systems perform under various conditions but does not inherently target identification of risks associated with functionality or behavior. Specification-based Testing is guided by requirements, which may not fully capture the dynamic nature of the environment. Thus, Error Guessing stands out as the most suitable choice for this context.