I was used in the Chinese economy. Oftentimes, I had holes in me so that I could be
carried on a string. I made trade across the
Zhou empire much easier. Who am I?

no

Explanation:

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.