With the engine off and the ignition switch in the run position the oil pressure gauge should indicate a reading of __ a. Three b. Two c. One d. Zero

The correct answer is d. Zero.<br /><br />When the engine is off and the ignition switch is in the run position, the oil pressure gauge should indicate a reading of zero. This is because the engine is not running, and there is no oil pressure being generated. The oil pressure gauge is designed to measure the pressure of the oil being pumped by the oil pump when the engine is running. When the engine is off, there is no oil pressure, and the gauge should read zero.