<span>paying taxes, raising armies, and providing other services for their lord is that that is what the guilds did for their lord in return
I hope that helped and is right </span>
I think that the best answer is "c. an incentive to bring their ideas to market" - you can see that through the statement of "<span>the opportunity to profit from their ideas"- an opportunity to profit is an incentive to work and in the case of the creators - to bring their ideas to market.
However, an opportunity to profit is not a guarantee that one will profit - so for example option a) is wrong. </span>
