Which of the following is an example of frictional unemployment? A. Dave searches for a new job after voluntarily moving to San Diego. B. Elaine is willing to work for less than the minimum wage, but employers cannot hire her. C. Bill is qualified and would like to be an airline pilot, but airlines do not find it profitable to hire him at the wage established by the airline pilot's union. D. Joan is willing to work at the going wage, but there are no jobs available.