To the Degree That the IBEW Conducts Costly Training and Apprentice

To the degree that the IBEW conducts costly training and apprentice requirements for prospective electricians, it is

A) shifting the supply of electricians to the left.
B) shifting the supply of electricians to the right.
C) shifting the demand for electricians to the left.
D) kinking the supply of electricians to make it vertical at the level of the constraint.