Indicate whether the following events will increase, decrease, or have an uncertain effect on the quantity of labor demanded by U.S.

automobile manufacturers.

Event A: Demand for U.S. cars falls.

Event B: Wages of auto workers go up.

Event C: Price of machinery goes up. (Machinery and auto workers are complements.)

Event D: Price of machinery goes up. (Machinery and auto workers are substitutes.)

Event E: Total productivity goes up in U.S. auto making. Demand for U.S. cars is elastic.