Step-by-step explanation:
This is actually a very old riddle, but it is two guards and two doors life death .
So let's apply the same logic to this one.
You only meet one villager and you don't know if he is one of the ones who only tells the truth or always lies, to answer this riddle, the question is actually to an hypothetical third party, another villager, not present, this is a little convoluted so bear with me:
(Pointing to one of the roads): If I asked another villager if this road would lead me to the ruins, would he be correct?
If the villager is a truth one, the true-villager, would tell you that the liar-villager would say no (thus leading you to the jungle).
Therefore, no matter what villager you run into, the question will always lead you to the jungle, and therefore you pick the other road.