Which of the following is a characteristic of an open system?

An open system is characterized by a high level of user interaction with sample processes. This means that users have the ability to engage directly with various stages of the process, allowing for adjustments, modifications, and interventions as deemed necessary. This interaction may enhance user control over the system and can lead to better outcomes based on individual needs or specific sample types.

In contrast, options that suggest automation, low susceptibility to human error, or inflexible protocol modification pertain more to closed systems. Closed systems are typically designed for automation, which minimizes direct user interaction and reduces the likelihood of human error, thereby streamlining processes based on predetermined protocols. However, this also limits the user's ability to make real-time modifications, making them less adaptable compared to open systems. Thus, the defining trait of an open system revolves around its user engagement, allowing for a dynamic process that can be tailored to meet various requirements.