E is extremely poorly worded! My understanding is that E is effectively the opposite of C. That is, c is saying that the supposed legal rule may not actually be a legal rule, but E is saying that the rule in question has been consistently upheld by higher courts. That is, I would read E as saying that higher courts (and the use of the term superior is odd here, since that could mean different things in different contexts) have ruled in a constant manor as to the validity or application of the rule in question. Thus, there is not uncertainty as to the rules legality or application.
