The answer to your question would be that the literary device that enables readers to have mulitiple interpreations of a word, phrase, or event is the following one: ambiguity. That is, the correct option would be C.
Ambiguity, also known as fallacy of ambiguity, is a word, phrase, or statement which contains more than meaning. These words or statements lead to confusion. For instance, "Yesterday I rode a horse with sunglasses" is ambigous because it can be taken as if the one with the sunglasses was the horse.
The figurative language that is used by Mr Shiflet reveals that he is a character who is intelligent and wise. To be able to use an appropriate analogy requires knowledge and experience. This means that Mr Shiflet is old and has gone through a lot of things in his life.
I say it is probably b because law is a list of rules to go by ladder don’t really know but pretty sure it doesn’t mean that I’m assuming it is b because we learned that a long time ago but don’t know if it the same meaning for you