A few of these answers could work but I think A or C would be most fitting!
Answer: It means an earlier event or action that is regarded as an example or guide to be considered in subsequent similar circumstances.
Explanation:
I'm not good with religious things, but I think this might be helpful: https://www.wikihow.com/Confess-Sins
Answer:
there is no option but idiom is an expression or phrases whose meaning doesn't relate to literal meaning of it words