(A) a series of swift and decisive battles
(B) lightening quick strikes known as “blitzkrieg”
(C) navy battles fought in the Pacific Ocean
(D) ** a war of attrition fought primarily in trenches
EXPLANATIONS BELOW
Concept note-1: -World War I was a war of trenches. After the early war of movement in the late summer of 1914, artillery and machine guns forced the armies on the Western Front to dig trenches to protect themselves.
Concept note-2: -During World War I, trench warfare was a defensive military tactic used extensively by both sides, allowing soldiers some protection from enemy fire but also hindering troops from readily advancing and thus prolonging the war. Trench warfare was the major combat tactic in France and Belgium.
Concept note-3: -While the war on the Western Front developed into trench warfare, the battle lines on the Eastern Front were much more fluid and trenches never truly developed. This was because the greater length of the front ensured that the density of soldiers in the line was lower so the line was easier to break.
Concept note-4: -Trenches were common throughout the Western Front. Long, narrow trenches dug into the ground at the front, usually by the infantry soldiers who would occupy them for weeks at a time, were designed to protect World War I troops from machine-gun fire and artillery attack from the air.