The Main Reason Firms Cannot Price-Discriminate Under Perfect Competition Is

The main reason firms cannot price-discriminate under perfect competition is because:

A) firms are price-takers and cannot set prices for their goods.
B) firms cannot identify different kind of consumers perfectly.
C) some goods are being resold in the market.
D) there is a lot of heterogeneity among consumers' tastes.
E) all firms share the same production technology.