Newspaper editor: Law enforcement experts, as well as most citizens, have finally come to recognize that legal prohibitions against gambling all share a common flaw: no matter how diligent the effort, the laws are impossible to enforce. Ethical qualms notwithstanding, when a law fails to be effective, it should not be a law. That is why there should be no legal prohibition against gambling. Which one of the following, if assumed, allows the argument's conclusion to be properly drawn? ['Most citizens must agree with a law for the law to be enforceable.', 'No effective law is unenforceable.', 'No legal prohibitions against gambling are enforceable.', 'Most citizens must agree with a law for the law to be effective.']