(A) ** The U.S. government abandoned its official policy of neutrality.
(B) Germany financed the Mexican army’s attempted invasion of the United States
(C) Germany’s navy blockaded several Mexican seaports
(D) The U.S. government boycotted goods imported from Europe
EXPLANATIONS BELOW
Concept note-1: -Germany’s resumption of submarine attacks on passenger and merchant ships in 1917 became the primary motivation behind Wilson’s decision to lead the United States into World War I.
Concept note-2: -In 1915, the Germans used poison gases against the Allies fighting in the trenches on the Western Front. To protect soldiers from chemical warfare, gas masks were developed. Great Britain made one of the first types of masks capable of minimizing the deadly impact of these gases on their troops.
Concept note-3: -Background. Weapons played a big part in creating the difficult and unusual circumstances of trench warfare which the British Army encountered during the First World War (1914-18). The destructive power of modern artillery and machine guns forced soldiers to seek cover on the battlefield and dig in for protection.
Concept note-4: -Disease and ‘shell shock’ were rampant in the trenches. As they were often effectively trapped in the trenches for long periods of time, under nearly constant bombardment, many soldiers suffered from “shell shock, ” the debilitating mental illness known today as post-traumatic stress disorder (PTSD).