(A) by disguising themselves with flags of neutral nations
(B) by stopping vital supplies from reaching the front lines
(C) ** by attacking merchant ships without letting passengers flee to safety
(D) by conducting surprise searches of merchant ships in neutral waters
EXPLANATIONS BELOW
Concept note-1: -Germany possessed U-Boats but not in numbers sufficient to maintain a blockade, so the destruction of shipping with those U-Boats was illegal. And international law obligated warships to stop and inspect neutral vessels in order to check for illegal contraband-they could not just blow them up based on suspicion.
Concept note-2: -On May 6, the German government signed the so-called Sussex Pledge, promising to stop the indiscriminate sinking of non-military ships.
Concept note-3: -They hoped to break the British stranglehold blockade of crucial German supply ports and knock Britain out of the war within the year. U-boats resumed unrestricted attacks against all ships in the Atlantic, including civilian passenger carriers.
Concept note-4: -How did Germany’s U-boats violate international law? By attacking merchant ships without letting passengers flew to safety. How did president Wilson respond to the sinking of the Lusitania in 1915?