Question

the thermostat for the engine cooling system is designed to: (select all that apply.) open when the engine temperature needs to be cooled, this allows the flow of coolant through the radiator cooling it in the process allow the engine to reach operating temperature close to restrict the flow of coolant when the engine temperature is not hot

Explanation:

1. For the first option: A thermostat in an engine cooling system opens when the engine is hot (needs cooling) to let coolant flow through the radiator, which cools the coolant (and thus the engine). This is a key function of a thermostat.
2. For the second option: When the engine is cold (starting up), the thermostat is closed, which restricts coolant flow through the radiator. This helps the engine warm up faster to its operating temperature. So this is a correct function.
3. For the third option: When the engine temperature is not hot (cold or at lower temperatures), the thermostat closes. This restricts coolant flow through the radiator, allowing the engine to warm up (as explained in the second option) and also prevents unnecessary cooling when the engine doesn't need it. This is a correct function.

Answer:

A. open when the engine temperature needs to be cooled, this allows the flow of coolant through the radiator cooling it in the process
B. allow the engine to reach operating temperature
C. close to restrict the flow of coolant when the engine temperature is not hot