What technology can be used to locate a device such as a laptop after it has been stolen?

LoJack is the technology that can be used to locate a device such as a laptop after it has been stolen.

It is a tracking system that you can install in your devices, and you can track it down in case it gets stolen or you simply lose it. The other options cannot perform such a task, and a Trojan is a virus, so you shouldn't even have it in your computer, let alone use it as a tracking device.