Adapted from Woodrow Wilson’s "War Message to Congress" ("Address of The President of the United States Delivered at a Joint Session of The Two Houses of Congress") (April 2, 1917)

On the third of February last I officially laid before you the extraordinary announcement of the Imperial German Government that on and after the first day of February it was its purpose to put aside all restraints of law or of humanity and use its submarines to sink every vessel that sought to approach either the ports of Great Britain and Ireland or the western coasts of Europe or any of the ports controlled by the enemies of Germany within the Mediterranean.

That had seemed to be the object of the German submarine warfare earlier in the war, but since April of last year, the Imperial Government had somewhat restrained the commanders of its undersea craft in conformity with its promise then given to us that passenger boats should not be sunk and that due warning would be given to all other vessels which its submarines might seek to destroy when no resistance was offered or escape attempted, and care taken that their crews were given at least a fair chance to save their lives in their open boats. The precautions taken were meager and haphazard enough, as was proved in distressing instance after instance in the progress of the cruel business, but a certain degree of restraint was observed.

The new policy has swept every restriction aside. Vessels of every kind, whatever their flag, their character, their cargo, their destination, their errand, have been ruthlessly sent to the bottom: without warning and without thought of help or mercy for those on board, the vessels of friendly neutrals along with those of belligerents. Even hospital ships and ships carrying relief to the sorely bereaved and stricken people of Belgium, though the latter were provided with safe conduct through the proscribed areas by the German Government itself and were distinguished by unmistakable marks of identity, have been sunk with the same reckless lack of compassion or of principle.

I was for a little while unable to believe that such things would in fact be done by any government that had hitherto subscribed to humane practices. [International maritime law] the German Government has swept aside under the plea of retaliation and necessity and because it had no weapons which it could use at sea except these which it is impossible to employ as it is employing them without throwing to the winds all scruples of humanity or of respect for the understandings that were supposed to underlie the intercourse of the world. I am not now thinking of the loss of property involved, immense and serious as that is, but only of the wanton and wholesale destruction of the lives of noncombatants, men, women, and children, engaged in pursuits which have always, even in the darkest periods of modern history, been deemed innocent and legitimate. Property can be paid for; the lives of peaceful and innocent people cannot be. The present German submarine warfare against commerce is a warfare against mankind.

It is a war against all nations. American ships have been sunk, American lives taken, in ways which it has stirred us very deeply to learn of, but the ships and people of other neutral and friendly nations have been sunk and overwhelmed in the waters in the same way. There has been no discrimination. The challenge is to all mankind. Each nation must decide for itself how it will meet it. The choice we make for ourselves must be made with a moderation of counsel and a temperateness of judgment befitting our character and our motives as a nation. We must put excited feeling away. Our motive will not be revenge or the victorious assertion of the physical might of the nation, but only the vindication of right, of human right, of which we are only a single champion.

Based on the way in which it is used in the passage, the bolded and underlined word "belligerents" is used to mean which of the following, specifically?

A. People or groups who pester other people or groups and do things to undermine them without outright attacking them

B. Countries that are formally at war with another country

C. Countries whose ports are assailed by ships from other countries

D. Pirate captains and crews who do not follow the rules of maritime law