(A) ** France
(B) Great Britain
(C) United States
(D) Italy
EXPLANATIONS BELOW
Concept note-1: -The majority of the fighting took place in Europe along two fronts: the western front and the eastern front. The western front was a long line of trenches that ran from the coast of Belgium to Switzerland. A lot of the fighting along this front took place in France and Belgium.
Concept note-2: -Although fighting occurred worldwide, the bulk of the conflict in Europe occurred in Belgium, Luxembourg, France and Alsace-Lorraine along what came to be known as the Western Front, which consisted mainly of trench warfare.
Concept note-3: -The Western Front was the place where the most powerful military forces in Europe, the German and French armies, met and where the First World War was decided.
Concept note-4: -FRANCE ENTERS WORLD WAR I German troops were readied to invade France, through Belgium with the plan of attack known as the Schlieffen Plan. In fact, Germany formally declared war on August 1st against France, Belgium, and Russia. In response, France mobilized its forces and readied for war with Germany.
Concept note-5: -It was fought between two coalitions, the Allies (primarily France, the United Kingdom, Russia, Italy, Japan and the United States) and the Central Powers (led by Germany, Austria-Hungary, and the Ottoman Empire). Fighting occurred throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia.