In which year did the First World War (World War I), a global conflict involving many of the world’s great powers, officially break out?

Introduction / Context:
This question checks your basic knowledge of world history, specifically the dates of major global conflicts. The First World War, also known as World War I, dramatically reshaped international politics, empires and societies. Knowing the year in which this war officially began is fundamental for understanding 20th century history and for answering many related questions in exams.

Given Data / Assumptions:

• The conflict is the First World War (World War I).
• The question asks in which year it broke out.
• The options are 1904, 1914, 1924 and 1934.
• We assume awareness that the war lasted from 1914 to 1918.

Concept / Approach:
World War I is universally dated as beginning in 1914 and ending in 1918. The immediate trigger was the assassination of Archduke Franz Ferdinand of Austria in June 1914, followed by a series of diplomatic crises and declarations of war in July and August. None of the other years listed match the well established period of this war. Therefore, identifying the start year is mainly a matter of correctly recalling the basic timeline of the conflict.

Step-by-Step Solution:
Step 1: Recall the standard dates of World War I: 1914–1918. Step 2: Focus on the year in which hostilities officially began, which is 1914. Step 3: Compare this date with the options: 1904 (too early), 1924 and 1934 (too late). Step 4: Select 1914 as the correct year when the war broke out.

Verification / Alternative check:
Any world history textbook or reference work confirms that World War I began in 1914, following the assassination in Sarajevo and the July Crisis. Key events include Austria Hungary's declaration of war on Serbia and subsequent mobilisations by other powers. The year 1918 is recorded as the end of the war with the armistice. None of the other years listed in the options are associated with such a global conflict under the name World War I.

Why Other Options Are Wrong:
1904: This year is associated more with the Russo Japanese War, not with World War I.
1924: Comes after the war and falls in the interwar period; it is linked more to postwar reconstruction and the League of Nations, not the outbreak of World War I.
1934: Belongs to the interwar years leading up to World War II, not to the start of World War I.

Common Pitfalls:
Some students mix up the start dates of the two World Wars, sometimes mistakenly placing World War I at 1919 or 1939. Others may confuse the war's end date (1918) with its start date (1914). A simple memory aid is to remember the pair 1914–1918 as the bracket for World War I and 1939–1945 for World War II, keeping the timelines clearly separated in your mind.

Final Answer:
World War I broke out in the year 1914.