(A) Germany bombed America
(B) Britain declared war on the U.S.
(C) ** Germany used unrestricted submarine warfare
(D) France invaded Germany
EXPLANATIONS BELOW
Concept note-1: -Answer and Explanation: The main result of Germany’s use of unrestricted submarine warfare during World War l was the entry of the United States into the conflict. Submarines had been attacking the ships of neutral countries, as well as, ships that carried civilian passengers.
Concept note-2: -What were the main reasons for U. S. involvement in the war? The main reasons the US got involved in the war was because of nationalism, imperialism, militarism, and forming allies.
Concept note-3: -Why did the Germans resort to unrestricted submarine warfare? Germany wanted to break the deadlock in the war where the British kept war materials and other goods from reaching Germany by a naval blockade. The German blockade of Britain could only be effective if they went after passenger and other ships.