Some federal government insurance programs provide coverage for loss exposures that private insurers have avoided largely because of the potential for catastrophic losses. An example of such a program is

The National Flood Insurance Program (NFIP) provides flood coverage because private insurers largely avoid flood risk due to catastrophic loss potential from single events. Workers comp (A) and auto insurance (C) are readily available privately. Unemployment insurance (B) is government-provided but not designed for catastrophic risks - it addresses economic cycles, not natural disasters.