Suppose that the Electrical Workers Union requires a five-year apprenticeship period before granting full membership to new workers. The most likely reason for this long apprenticeship period is:

a. to ensure that some relatively low paid electricians are qualified for jobs that do not require a high degree of specialization.

b. To restrict entry into the trade and thus maintain relatively high wages.

c. To assure the market that a large, highly trained supply of electricians will always be available.