The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
What did Henry Demarest Lloyd mean when he said “The safety of civilization is the highest law,” was that it was of the utmost importance to keep the American people informed about the injustices and the corruption activities in the country. This way, society could aspire to moral acts that represented justice, safety, and harmony for all.
Demarest took that quote from Cicero, the great Consul of ancient Rome.
Henry Demarest Lloyd(1847-1903) was an American journalist during the progressive era, who started to investigate and expose the corrupt practices of businessmen and politicians in what was known as "muckraking journalism."