Answer:
The correct answer is d. c. structural unemployment.
Step-by-step explanation:
Structural unemployment is due to the fact that the number of existing jobs is insufficient to give employment to everyone who wants a worker (active population).
When a union raises wages above the equilibrium level, it increases the supply of employment and reduces demand. This generates unemployment.
• Internal workers benefit from high salaries earned in negotiation collective
• External workers have difficulties in find a job or have to accept a job in a non-union company.