The second battle at the river marne between german troops and the combined forces of french and american troops
a. proved to be one of the bloodiest battles of world war i.
b. united french and american forces for the first time.
c. ended any german hope for victory.
d. was the point of american entry into the war.

The second Battle at the river Marne between German troops and the combined forces of French and American troops ended any German hope for victory. The correct option in regards to all the options given in the question is option "c". The second Battle of the Marne was also known as the Battle of Reims was fought between 15th of July to 6th of August in the year 1918. This war led to the Armistice of Germany about 100 days later.

James wattrichard arkwright eli whitney thomas edisonnicolaus otto