Answer:
A. A bomb shelter
Explanation:
There are still many houses that have a bomb shelter in place, either under the house or in the backyard, still stocked for post-apocalypse. Bomb shelters are sturdy for they are built into the ground, which can absorb most of the shock waves caused by a bomb (in this case, a nuclear weapon). They can also hold out for long periods of time, which is needed in an event of a nuclear weapon (which has nuclear fallout).
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