To find the cause of a gasoline engine's failure to start, you should __________.

Correct Answer: Option A — ventilate the space, then check the battery, spark plugs, carburetor, and fuel line

Safety regulations mandate clearing volatile explosive vapors from machinery spaces before troubleshooting electrical or mechanical ignition components. Checking core components systematically while prioritizing ventilation minimizes the risk of catastrophic fuel-air deflagration during troubleshooting.