What is a significant limitation of VHF communication?

The correct answer highlights the characteristic of Very High Frequency (VHF) communication that it typically has a limited range and generally broadcasts to the horizon. VHF signals travel in straight lines and are primarily affected by the curvature of the Earth, which limits their effective range to line of sight. This means that unless there is a repeater or the antennas are placed at considerable heights, communication over long distances can be challenging. This limitation can affect operations, especially in maritime and aviation contexts, where the horizon distance can significantly restrict communication capabilities.

While other options address certain aspects of VHF communication, they do not encompass the fundamental constraint of range in the way that this answer does. For example, while VHF can indeed be influenced by physical obstructions or may seem weather-dependent under specific conditions, the essence of its functionality primarily revolves around the line-of-sight transmission, making the limited range an integral and significant limitation.