The system, which developed in europe, began when groups of artisans banded together to establish prices and support their trade. a. pnyx b. leisure c. tax d. guild

I believe the correct answer would be D. guild.
Hope it helps!

D. guild

A guild is an association of artisans or merchants who oversee the practice of their craft in a particular town. The earliest types of guild were formed as confraternities of tradesmen. They were organized in a manner something between a professional association, trade union, a cartel, and a secret society. They often depended on grants of letters patent by a monarch or other authority to enforce the flow of trade to their self-employed members, and to retain ownership of tools and the supply of materials. A lasting legacy of traditional guilds are the guildhalls constructed and used as meeting places.