A ___ is a line between two converging forces, No fires ( direct or indirect) or their effects across the line are allowed without coordination with the affected force.

• A. Final Protective Line
• B. Coordinated Fire Line
• C. Restrictive Fire Line (RFL)
• D. Observation Line

Answer: (C)

The idea being tested is how fire support boundaries manage safety when two forces move toward each other. A boundary that sits between converging forces and forbids any fires or their effects crossing it without approval from the affected unit is a restrictive fire line. This line helps prevent fratricide and misdirected fire as units maneuver, ensuring that any cross-line firing is deliberately coordinated and agreed upon.

Understanding the contrast helps: a coordinated fire line also requires approval to cross, but once coordination is established, crossing is permitted; this is a slightly looser restriction than the strict no-cross rule of the restrictive fire line. A final protective line serves a different defensive purpose—it designates where fires are allocated to stop an enemy at the last moment—rather than governing cross-boundary fire between converging friendly forces. An observation line, on the other hand, is about where observers can view targets, not about controlling where fires can go.