The principle keys entirely on one thing, whether the act that caused death was rash or negligent, and it does not ask about intention, location, or what else happened to the person who caused the death. That framing narrows the analysis considerably.
Driving an SUV at 160 kilometres per hour on any road is an extreme, uncontrolled speed, and doing so on a road leading into a forest, where a person could plausibly step out, makes the risk foreseeable rather than freakish. That combination of extreme speed and foreseeable risk is what rashness means under the principle, and it is present here independent of whether X meant any harm.
The road being lonely, X lacking any intent to kill, and X himself being injured are all facts about the surrounding circumstances or the aftermath, none of them touch the actual question of whether the manner of driving was rash. Once the rash driving is established as the cause of death, the principle's offence is made out.
So the correct answer is X is guilty of an offence death by rash or negligent act.
Checking what fact would need to change for each option to be correct clarifies things quickly.
Since the extreme speed and foreseeable risk already establish rashness on their own, and none of the three alternative conditions actually appear in the principle, the option finding X guilty is the one that fits without needing any unstated fact.
Therefore, the correct answer is X is guilty of an offence death by rash or negligent act.