Which of the following was not a unique chinese achievement?

a. creation of porcelain

b. development of silk

c. establishment of cities

d. invention of paper

A and B is out because these undoubtedly are unique Chinese achievements. So is D. The Chinese are infamous for these things. Other achievements include gunpowder, fireworks, ect. C is basically the answer because the chinese aren't the only race or country to do so. Many people have done it in the past before them and present in the terms of civilization. It isn't simply uniquely or originally from them.