During the golden age, what allowed shops to conduct business using a form of credit similar to modern day checks?
a. a publication law passed by the empire's government
b. the arrival of scholars who could teach the method
c. the discovery of the chinese paper making
d. the introduction of a copying technique using ink

The answer would be : C. The discovery of chinese paper making

Before the discovery, writing was usually done on top of parchment or papyrus. This method takes a longer time to be done and harder to produce. After the discovery, business started to realize the efficiency of the chinese-made paper and start using it as the equivalent of modern day checks.

hope this helps