I think the correct answer should be the Letter A.
The major world religion which teaches that people will achieve freedom by following the Eightfold Path is a) Buddhism. The Eightfold Path is one of the principal teachings within Buddhism and is used to develop insight into the true nature of phenomena and reality and is used to eradicate greed, hatred and delusion.
I don't believe a or b is the answer so i would eliminate those 2
Khan Academy is a good one. Or Coursera.