Which of the following would be a good summary for a defect report that captures the essence of a failure in an online banking system?

The correct choice effectively summarizes a specific failure in the online banking system by clearly describing a typical real-world scenario that users are likely to encounter. It outlines the direct impact of a defect: during a funds-transfer transaction, the system terminates the customer’s session and introduces delays in availability. This level of detail provides immediate insights into the nature of the issue, indicating both a functionality problem (session termination) and a performance concern (delay in availability).

By focusing on a typical transaction, the summary ensures that developers have context regarding when and how the defect occurs, which is crucial for effective troubleshooting and resolution. This specificity not only conveys the severity of the defect but also helps prioritize the issue based on its potential impact on user experience in a banking system, where reliability and performance are paramount.

Other options, while they touch on relevant issues, lack the specificity and contextual understanding that this choice provides. For instance, mentioning an error code or general statements about the impact on customers may not convey the precise issue as clearly as detailed observations about transaction behavior.