Suppose That a Professional Association Strengthened the Limits to Entry

Suppose that a professional association strengthened the limits to entry into their profession and at the same time lengthened its required apprenticeship program.The likely effect would be that

A) the supply curve for labour would shift to the left.
B) the supply curve for labour would shift to the right.
C) both the demand and supply curves for labour would shift to the left.
D) the demand curve for labour would shift to the right.
E) there would be an increase in the quantity of labour supplied.