It would be pleasant if it were immediately obvious from our initial diagram which answer violated a rule. But it may not always be. To avoid playing out each conditional, first we should make use of our past work to eliminate some legitimate pairs.
The answer from Question 1 indicates that M-O is acceptable, so we can eliminate (D).
The answer to Question 2 indicates that L-O is acceptable, so we can eliminate (B).
At this point, it would be strategic to note that N and O are the only possible players for stop 5, and thus, may be the most dangerous to mess with. That fact makes (E) a strategic case to test first.
If O is at stop 1, it must also be at stop 6. If N is at stop 2 it must also be at stop 4. Check out the diagram:
But no two consecutive stops may be the same, and yet stop 5 must be either N or O! There's no way to proceed without violating one of the rules. (E) is the correct answer!
Another Perspective: Frames
If we had framed the divide between N and O at stop 5, we could have potentially saved ourselves some work. There are not a ton of positive inferences to make in these frames, but there are a number limitations imposed.
In both frames, O is banned from stop 1! (E) would jump out as a clear rule violator with these frames.
There are multiple lines of attack on questions like this: original inferences, framing, using previous work, strategically noting dangerous rule combos, and when all else fails, plugging in the answer choices to find the rule violator.