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.