Which of the following statements about the idea that people are rational is correct?

A$.$ The idea assumes that consumers and firms always make correct decisions.

B$.$ The idea assumes that consumers and firms use all available information as they act to achieve their goals.

C$.$ The idea assumes that consumers and firms take into account the benefits of their actions but ignore the costs.

D$.$ The idea assumes that consumers and firms take into account the costs of their actions but ignore the benefits.