During engine warm-up, when the thermostat is closed, _____.
A) coolant flows through the radiator
B) coolant flows through the bypass passage
C) both "coolant flows through the radiator" and "coolant flows through the bypass passage"
D) neither "coolant flows through the radiator" nor "coolant flows through the bypass passage"

Question

Quizplus · Accepted Answer

During engine warm-up, the thermostat remains closed to prevent coolant from flowing through the radiator. Instead, the coolant circulates through the bypass passage to allow the engine to reach its optimal operating temperature more quickly.

During Engine Warm-Up, When the Thermostat Is Closed, _____