Answer:
I think it is either A or D
Well civilization helped with that before all of these inventions people ad to hunt and gather what they saw and the inventions that helped us were the Corn Picker, Cotton Gin,<span>Cotton Harvester and many more</span>
The policy is known as the "Open Door Policy."
John Hay created this idea in hopes that America and countries all over Europe could trade peacefully with China. This concept was developed in order to protect America's trade interests while also ensuring that no other country would establish a monopoly on trade with China. Within this policy, all countries would agree not to interfere with another country's trade with China.
