Which of the following types of fire is caused by a mechanical issue?

The type of fire caused by a mechanical issue is a car fire. Car fires frequently stem from mechanical failures such as electrical shorts, fuel line leaks, or overheating due to engine problems. These issues can create sparks or ignite fuel, leading to a fire that can spread quickly given the presence of fuel, oils, and other flammable materials found in vehicles.

In contrast, grass fires are typically caused by natural elements such as lightning or human activities like campfires or discarded cigarettes. Boat fires may arise from various causes, including electrical issues or fuel leaks, but they are not primarily categorized as mechanical issues when directly compared to the consistent mechanical nature of car fires. Trash fires can be ignited by improper disposal of flammable materials or intentional acts but do not typically involve mechanical components that contribute to ignition. Understanding the common causes of each fire type helps in preventing and responding to fire hazards effectively.