Madison Kelp owns three boats, which participate in commercial fishing for fresh Pacific salmon off the coast of British Columbia. As part of her business, she hires a captain and several crewmembers for each boat. In the market for fresh Pacific salmon, there are thousands of firms like Madison's. While Madison usually catches a significant number of fish each year, her contribution to the entire harvest of salmon is negligible relative to the size of the market.

In the fresh Pacific salmon product market, what does Madison control?

a) the wage she pays her workers
b) the quantity of fresh salmon that she catches and supplies to the market
c) the competitive environment of the market
d) the price she charges for her fresh salmon