What indicates an FPCON level 'Charlie'?

The correct choice indicates a specific alert level where there is credible intelligence suggesting that terrorist activity is imminent, which necessitates a heightened state of readiness and vigilance. In FPCON Charlie, security forces are placed on notice due to the potential for a specific threat that has been identified through actionable intelligence.

This level is above the general heightened state of awareness that might accompany an increased general threat or a more predictable threat. While those conditions may lead to a change in readiness, they do not signify the same level of specificity and urgency as intel pointing directly to possible terrorist activity. FPCON Charlie requires immediate and potentially drastic measures to mitigate risk, reflecting the serious nature of the information received.