The zimmerman telegram gave the u. s. an ultimatum. offered mexico to hitler. tried to warn americans of the attack on the lusitania. turned americans against germany

 Turned Americans against Germany.

Explanation:

As Germany decided to resume unrestricted submarine warfare in the Atlantic, the idea behind the Zimmermann telegram was that Mexico would engage in war with the United States, which would keep US forces and funding occupied on its own continent and prevent them from jumping into the war in Europe.   The British intercepted and decoded the message, and knowledge of it turned American opinion strongly against Germany and the US declared war and joined the Allies.

Here is the decoded text of the telegram sent by German Foreign Secretary Arthur Zimmermann to the German ambassador to Mexico, Heinrich von Eckardt:

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

an expansion is one of two basic business cycle phases; the other is contraction. the transition from expansion to contraction is a peak, and the changeover from contraction to expansion is a trough.