Survivalism is a movement of individuals or groups (called survivalists or preppers) who actively prepare for emergencies, including possible disruptions in social or political order, on scales from local to international. Survivalism also encompasses preparation for personal emergencies, such as job loss or being stranded in the wild or under adverse weather conditions. The emphasis is on self-reliance, stockpiling supplies, and gaining survival knowledge and skills. Survivalists often acquire emergency medical and self-defense training, stockpile food and water, prepare to become self-sufficient, and build structures such as survival retreats or underground shelters that may help them survive a catastrophe.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!