What action should be taken when a client is overwhelmed by high transaction volumes?

The option that suggests considering rate limiting measures is a practical response to a client overwhelmed by high transaction volumes. Rate limiting involves controlling the number of requests a client can make to a server in a certain time period. This approach can help to manage server load and ensure that the system remains responsive, thereby preventing performance degradation or failures during peak usage times.

Implementing rate limiting can also provide a better user experience, as it helps to prevent system overload and ensures that legitimate transactions are processed smoothly. By introducing controls on how many transactions can be processed within a specific timeframe, businesses can maintain an efficient service while managing high transaction volumes effectively. This approach is more about the technical management of the infrastructure rather than changes to policy or thresholds, which might not address the root technical challenges posed by high transaction loads.