Closed-loop operation requires all except which of the following? A. The oxygen sensor must reach operating temperature. B. The engine coolant temperature must be at or above a criterion temperature....

Closed-loop operation requires all except which of the following?

A. The oxygen sensor must reach operating temperature.

B. The engine coolant temperature must be at or above a criterion temperature.

C. The vehicle speed must be at least 20 mph.

D. A predetermined amount of time must have elapsed since the engine was started.