Which of the following approaches to understanding and predicting consumer behavior does not actually solicit any information from any potential customers?

Define a budget set. Is it the same as a budget constraint?

What will be an ideal response?

The cost to a firm of producing one more unit of output

A) usually exceeds the firm's price. B) is significantly less than the firm's price for purely competitive firms operating in long-run equilibrium. C) usually equals the firm's price for monopolistically competitive firms. D) is the firm's marginal cost.