Which of the following correctly express the right time in which the farm tools were developed？

A.Stone tools in Neolithic age.

B.Bronze tools in Xia， Shang， Zhou dynasties.

C.Iron tools since Warring States perioD.D.Iron tools since Neolithic age.

正确答案：Stone tools in Neolithic age.Bronze tools in Xia， Shang， Zhou dynasties.Iron tools since Warring States period.