Which of the following is included in the 9 line skeleton for reporting?

The correct choice includes essential communication details that are critical during tactical operations. The nine-line format is a standardized method used by military personnel to relay information concisely and effectively. This format is particularly important for air support or medical evacuation requests, where clarity and precision can save lives.

Including radio frequency and call sign in the nine-line skeleton is vital as it allows for immediate and clear communication with the necessary units. Knowing the appropriate radio frequency ensures that the relaying team can establish contact with the right command or support elements. Similarly, providing a call sign helps identify the units involved, which is crucial in reducing confusion during fast-paced and complex operations.

The other options, while relevant in different contexts, do not fit the specific requirements of the nine-line skeleton for reporting in this instance. Enemy's last known location is more operational intelligence than a communication protocol, while weather conditions and allied troop movements pertain to situational awareness and planning rather than the immediate reporting structure outlined in the nine-line format.