You are driving a manual-transmission truck. To take a long, steep downhill grade, what gear will you use?

A A lower gear than you would use to climb the hill.

explanation

Before starting down a hill, slow down and shift down to a speed that you can control without using the brakes hard. Otherwise, the brakes can overheat and lose their braking power. Make sure you are in a low enough gear, usually lower than the gear required to climb the same hill. [California Commercial Driver Handbook]