What is the primary function of a guided missile?

The primary function of a guided missile is to have its flight path altered by guidance. This guidance is crucial as it enables the missile to adjust its trajectory in real-time in response to target movements and other factors during the flight. Unlike unguided missiles, which follow a predetermined path and cannot adjust after launch, guided missiles utilize various systems such as GPS, radar, or infrared to actively steer themselves toward their target, improving accuracy and effectiveness.

This ability to receive updates or corrections during flight distinguishes guided missiles and is fundamental to their design, ensuring they can effectively engage moving or relocating targets. The other options describe functionalities that do not align with the core purpose of a guided missile. For example, the notion of operating independently without external input disregards the essential guidance systems that define guided missile operation. Similarly, remaining stationary until activated implies a different type of weapon system. Detonating upon impact, while a characteristic of some missiles, does not encompass the role of guidance in targeting throughout the missile's flight.