Final answer:
The coolant is directed through the bypass circuit to allow the engine to warm up more quickly by avoiding heat loss through the radiator. So, the correct option is c) the coolant is cycled primarily through the engine
Step-by-step explanation:
When the thermostat routes the coolant through the bypass circuit, the coolant is cycled primarily through the engine rather than through the radiator.
This usually occurs when the engine's temperature is below its optimal operating range.
By bypassing the radiator, the coolant does not lose its heat to the outside air, which allows the engine to warm up more quickly.
Once the engine reaches its designed operating temperature, the thermostat will adjust to send coolant through the radiator to regulate the engine temperature by allowing heat exchange with the outside air.
Therefore, the correct option is c) the coolant is cycled primarily through the engine