The Short-Run Equilibrium in a Perfectly Competitive Market Is Determined

The short-run equilibrium in a perfectly competitive market is determined by the _____

A) intersection of the market demand and market supply curves.
B) intersection of the market demand and the largest firm's supply curve.
C) intersection of the market demand and the largest firm's marginal cost curve.
D) intersection of the market supply curve and the demand curve of the largest firm in a market.
E) intersection of the market supply curve and the most profitable firm's demand curve.