Suppose a Study Found That Union Wages Were 10% Higher

Suppose a study found that union wages were 10% higher than nonunion wages.Unions will have actually raised wages by more than 10% when

A) union workers who lost their jobs found work in the nonunion sector.
B) consumers shifted their demand to the lower priced nonunion goods.
C) nonunion employers raised their wages in response to the threat of being unionized.
D) union workers are more productive workers than nonunion workers.