What effect did John Hay's Open door policy letters have on the imperial powers of Britain, France, Germany, Russia, and Japan
A It provoked the imperial powers to declare war on the United States
B it caused the imperial powers to re-straight trade in their trade with China
C it warmed the imperial powers that the United States would soon declare war on China
D it signaled to those powers that the United States would take a larger role in world affairs then you