The correct answer is A) World War 1. Â
The war that begun the modern era was World War 1. Â
World War 1 was the first great war of the century. This was a global event that initiated on July 1914 until November, 1918. It was one of the largest, bloodiest, and deadliest conflicts in history of humanity. Historians believed that it mobilized almost 70 million military people. The battle was fought by two sides. One side was the alliance called the Triple Entente, formed by Russia, France, and Great Britain. The other side was the alliance called The Triple Alliance formed by Germany, Italy and Austria-Hungary. Eventually the Triple Entente won the war but a high cost.