If,beginning from a Competitive Labor Market,some Workers Form a Union

Multiple Choice

If,beginning from a competitive labor market,some workers form a union and negotiate a higher rate for themselves,which of the following is likely to happen?

A) Competition will force the wage rate in the non-union sector to increase to the level of the union wage.
B) The marginal product of labor curve will increase in the unionized sector.
C) Employment will move from the union to the non-union sector over time.
D) Employment will increase in the union sector because workers will be attracted by the higher union wage.