The correct answer is A) Much shorter.
World War I began in 1914. The British and French troops became involved in the fighting almost immediately. However, the US did not enter World War I until 1917. The United States adopted a policy of neutrality in 1914, as they hoped to avoid being involved in this war in Europe.
However, this policy changed when the US had constant conflict with Germany. The final straw was when the British intercepted the Zimmerman Telegram and informed the United States of what Germany was trying to do. Essentially, Germany was trying to get Mexico to invade the US so that they did not have to worry about the US helping the Allied powers. This resulted in the US officially joining the war in 1917, three years after Britain and France.
