Question

After Siddhartha Gautama reached enlightenment, he explained to his followers the
suffering in one's life.
Four Noble Truths/Eightfold Path
Oь Torah/Ten Commandments
Oc Eightfold Path/Ten Commandments
Od Upanishads/Vedas

Answer 1

I do believe it is the four noble truths/eightfold path.

Explanation:
the Torah is like the Bible of Judaism, and the Ten Commandments are for Christianity so it cannot be either of the ones with Ten Commandments so you could mark them off. I’m pretty positive Vedas is Hinduism scriptures so it can not be the last one. That leaves four nobles truths and eightfold path and suffering in ones life.