If a Union Succeeds in Shifting the Labour Supply Curve

If a union succeeds in shifting the labour supply curve to the left, it can achieve wages above the

A) competitive level and all workers will gain.
B) equilibrium level as well as increasing employment.
C) competitive level but will reduce the level of employment .
D) equilibrium level without affecting employment.
E) competitive level without a pool of unemployed workers seeking to work at the higher wage.