What is indicated by the ground-to-air symbol "▼"?

The ground-to-air symbol "▼" signifies that it is safe for an aircraft to land. This understanding is crucial for communication between ground personnel and pilots, especially in emergency or non-emergency situations where clarity is essential. By using this symbol, it conveys a clear message that the area is secure for landing, which is vital for the safety and coordination of aerial operations.

The other options, while they may represent other forms of communication or requests, do not align with the specific meaning of this symbol. Air traffic and ground personnel rely on standardized symbols to ensure effective communication, especially in potentially life-threatening situations. Understanding these symbols enhances a guide's ability to navigate and communicate effectively in the field.