Q: Crabs live in what sort of environment?
Options:
- maritime
- bodies of water
- saltwater
- galapagos
- fish market
A: Let me think step-by-step: Saltwater refers to the environment of the sea. Sea have salty water so sea creature get used to live in saltwater environment. crab is sea creature. The answer is saltwater.

Q: What type of breathing can be dangerous?
Options:
- stay alive
- continue to live
- hyperventilation
- relaxation
- panting
A: Let me think step-by-step: Breathing deeper and faster than normal is called hyperventilation. Breathing deeper and faster than normal decreases carbondioxide in the blood. Decreased levels of carbondioxide can be dangerous. The answer is hyperventilation.

Q: What would be built on a foundation of rock?
Options:
- pillars
- mountains
- bridge
- mountain range
- surface of earth
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Let me think step-by-step: Bridge is built on rock. Rock is foundation for any structure to be built. The answer is bridge.