Final answer:
The question does not provide a specific answer for a feature that shuts off the water heater at 210°F. Typical safety features include a temperature and pressure relief valve, but none of the given options match the condition exactly.
Step-by-step explanation:
The safety feature designed to shut off the water heater if the temperature exceeds 210°F is:
- shut off the water heater if the temperature exceeds 150°F
- shut off the water heater if the pressure exceeds 50 psi
- shut off the water heater if the gas supply is interrupted
- shut off the water heater if the pilot light goes out
However, the given options do not include a safety feature that specifically turns off the heater at 210°F. Typical water heater safety mechanisms include a temperature and pressure relief valve that might activate if temperatures get too high or pressure exceeds safe limits. For example, if the pressure exceeds 150 psi or the temperature reaches around 210°F, the valve will release water to cool down the system. Yet, without clear options that correspond directly to 210°F, a specific safety feature cannot be pinpointed based on the information provided.