Question: The buildup of military forces and the formation of a rigid military alliance system were major causes of which of the following wars?
A: The Spanish-American War
B: The First World War
C: The Second World War
D: The Vietnam War
Please eliminate two incorrect options first, then think it step by step and choose the most proper one option. Your answer should have exactly 5 paragraphs. Make sure that the last paragraph starts with the word "identity" and that each paragraph is separated by two new lines.
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