What component would you check if the engine had difficulty starting?

The battery condition is critical when diagnosing engine starting issues because the battery provides the necessary electrical power to start the engine. If the battery is weak, dead, or corroded, it may not deliver enough voltage to the starter motor, which is essential for cranking the engine. Signs of a failing battery include sluggish cranking, dim lights, or no response when turning the key.

In contrast, the other components listed do not directly impact the engine's ability to start. Windshield wipers, while important for visibility, have no bearing on the engine's starting mechanism. The air conditioning unit operates independently of the engine's starting process. Similarly, the power steering fluid affects steering ease, not the ignition or combustion process in the engine. Therefore, checking the battery is the best course of action when facing starting difficulties.