Which of the following could lead to overheated wiring?

Overheated wiring is typically caused by electrical issues that exceed the safe load capacity of the wires. Short circuits occur when there is a fault in the wiring that allows current to travel along an unintended path, resulting in an excessive flow of current. This surge of electricity generates heat, which can lead to overheating and potential fire hazards. Similarly, overloaded circuits happen when too many devices are connected to a single circuit, drawing more current than the wiring is rated to handle, thus causing an increase in heat.

In contrast, properly rated wiring is designed to handle specific electrical loads safely, while regular maintenance helps to identify and rectify potential issues before they escalate. Using heavier gauge wires can actually reduce the risk of overheating, as they are capable of carrying a larger amount of current without overheating. Therefore, the circumstances described in the correct choice are directly linked to conditions that can lead to overheated wiring.