Final answer:
The sinking of the Lusitania and the interception of the Zimmerman Telegram were key events that led to the US ending its neutrality and entering WW1.
Step-by-step explanation:
The correct answer is A) Lusitania; Zimmerman Telegram; neutrality.
The sinking of the Lusitania by a German U-boat and the interception of the Zimmerman Telegram by Great Britain were two significant events that led to the United States ending its neutrality and entering World War I to fight alongside the allies.
The sinking of the Lusitania, a British passenger vessel, in 1915, resulted in the deaths of 128 Americans. This incident outraged the American public and increased anti-German sentiment. However, it was not enough to push the United States into war.
The Zimmerman Telegram, intercepted in 1917, was a secret communication from the German foreign minister to the German ambassador in Mexico. It proposed an alliance between Germany and Mexico in the event that the United States entered the war. The telegram also suggested that Mexico should invade the United States and in return, Germany would help Mexico regain territory lost to the United States. When the contents of the Zimmerman Telegram were made public, it further fueled anti-German sentiment and played a significant role in swaying public opinion and pushing the United States to declare war on Germany.