Phil Harrison is a welder who works on skyscrapers and extension bridges. Phil's brother William is also a welder but he works in a manufacturing plant where he does all of his welding on ground level. Which of the following would not explain why Phil earns a higher wage than his brother?

Group of answer choices

cognitive dissonance

Phil has greater experience as a welder than his brother has.

Phil's marginal revenue product is greater than William's marginal revenue product.

Phil's job is more hazardous than William's job.