If violations of any of a society’s explicit rules routinely go unpunished, then that society’s people will be left without moral guidance.
Conclusion (Thus)
A society ought never to allow any of its explicit rules to be broken with impunity.
Evidence
violations of any people chaos explicit rule go → left without → results routinely moral unpunished guidance
Evaluate
The author is assuming that society ought to avoid chaos, and we should probably go along with that common sense assumption. It would be an unlikely answer to say,
The contrapositive of that conditional chain would say,
Isn't that what the conclusion is saying? Let's look closer.
What we said: don't let any explicit rule go routinely unpunished
What the conclusion says: never allow any explicit rule to go unpunished
What's the difference? The contrapositive of the chain the author presented in the evidence is saying we shouldn't let a rule go routinely unpunished. The conclusion is saying we shouldn't ever let a rule go unpunished.
Consider an example -- society has an explicit rule that you're not allowed to run a red light. You're a cop and you pull someone over for running a red light. They tell you that they're having a bathroom emergency and are rushing home / or you see they have a pregnant person in the backseat about to give birth. Should you punish them for running the red light or let them go unpunished?
According to the conclusion, you should never let any rule go unpunished!
But according to the evidence, it's potentially fine to let this rule go unpunished. You can't make a habit out of letting people run red lights with impunity, otherwise they'll all start doing it and chaos will result. But we weren't told of any danger associated with occasionally letting a broken rule go unpunished.
Goal
Let's look for an answer saying that the conclusion is stronger than what's warranted by the evidence. The author would be correct to say , but it's an unwarranted leap to say .