Which of the following best describes the purpose of a robust program?

A robust program is designed to effectively handle unexpected external issues without failure. This means that it can gracefully manage errors, unexpected inputs, or changes in the environment without crashing or producing incorrect results. A robust program is typically resilient and able to maintain its functionality in the face of unforeseen circumstances, which is crucial for reliability and trustworthiness in software applications.

The characteristic of handling unexpected external issues is fundamental to robustness because software is often deployed in dynamic environments where variables can change beyond the initial design assumptions. An effective robust program includes error handling and validation mechanisms that anticipate potential problems and manage them appropriately, ensuring continuous operation even when faced with difficulties. This resilience is what distinguishes a robust program from less adaptive coding practices.